CONFIDENTIAL 


FOR   OFFICIAL   USE   ONLY 


NOTES  ON  THE 


USE  OF  MACHINE  GUNS 
IN  TRENCH  WARFARE 


AND  ON  THE 


TRAINING  OF  MACHINE  GUN  UNITS 
COMPILED  FROM  FOREIGN  REPORTS 


•i 

V 


California 

.egional 

acility 

I 


ARMY  WAR  COLLEGE 


MARCH.  1917 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1917 


CONFIDENTIAL 


FOR   OFFICIAL   USE   ONLY 


NOTES  ON  THE 


USE  OF  MACHINE  GUNS 
IN  TRENCH  WARFARE 


AND  ON  THE 


TRAINING  OF  MACHINE  GUN  UNITS 
COMPILED  FROM  FOREIGN  REPORTS 


ARMY  WAR  COLLEGE 


MARCH.  1917 


WASHINGTON 

GOVERNMENT  PRINTING  OFFICE 
1917 


WAR  DEPARTMENT. 
Document  No.  580. 
Office  of  The  Adjutant  General. 


-tic. 


WAR  DEPARTMENT, 

WASHINGTON,  May  7,  1917. 

The  following  notes  on  the  use  of  machine  guns  in  trench  warfare 
and  on  the  training  of  machine-gun  units  are  published  for  the 
information  and  guidance  of  all  concerned. 

[2593173,  A.  G.  O.] 

BY   ORDER    OP   THE    SECRETARY   OP   WAR! 

H.  L.  SCOTT, 
Major  General,  Chief  of  Staff. 
OFFICIAL: 

H.  P.  McCAIN, 

The  Adjutant  General. 

3 


MACHINE  GUNS  IN  TRENCH  WARFARE, 


In  trench  warfare  as  it  exists  in  Europe,  automatic  machine  rifles, 
popularly  called  machine  guns,  find  their  greatest  use.  Besides  the 
trench,  the  essential  elements  of  a  trench  line  consist  of  a  depth  of 
wire  and  a  front  of  machine  guns. 

The  tremendous  stopping  power  of  machine  guns  enable  them  to 
replace  a  large  number  of  riflemen  along  this  line,  reducing  to  a 
minimum  the  men  employed  in  actual  defense,  thereby  leaving  a 
large  part  of  the  force  in  reserve  for  use  in  the  counter  attack,  or  for 
the  assumption  of  the  offensive  at  another  part  of  the  line.  Their 
use  also  reduces  the  daily  wastage  due  to  sickness,  and  prevents  the 
offensive  spirit  of  the  Infantry  from  becoming  impaired. 

Opposing  belligerents  in  the  present  European  struggle  soon  found 
it  necessary  to  greatly  increase  the  ratio  of  the  number  of  machine 
guns  per  1,000  Infantry  rifles  to  8,  and  in  some  areas  to  even  larger 
figures.  This  ratio  would  give  about  12  machine  guns  to  one  of 
our  maximum  strength  Infantry  regiments,  and  this  number  may 
be  assumed  as  the  minimum  that  would  be  required  to  properly 
defend  the  front  that  would  be  assigned  to  an  Infantry  regiment. 

Comparison  table  of  automatic  machine  rifles  in  most  general  use  in 

Europe. 


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6  MACHINE  GUNS  IN  TRENCH  WARFARE. 

TYPES  OF  AUTOMATIC  MACHINE  RIFLES.— The  term 

"machine  gun"  is  popularly  applied  to  all  rifles  of  this  character. 
Some  foreign  authorities,  however,  are  careful  to  apply  the  name 
"machine  gun  "  to  automatic  machine  rifles  of  the  Maxim,  Vickers, 
and  Colt  types  only,  calling  those  of  the  Lewis,  Light  Hotchkiss. 
and  Madsen  types  "Light  automatic  weapons,"  for  the  reason  that 
the  latter  are  a  cross  between  the  machine  gun  proper  and  the 
automatic  rifle.  The  term  ' '  automatic  rifle ' '  implies  a  weapon  which 
can  replace  the  ordinary  magazine  rifle  in  the  hands  of  the  individual 
soldier. 

The  powers  and  limitations  of  these  two  classes  of  automatic 
machine  rifles  have  been  carefully  studied  and  each  is  used  for  the 
work  to  which  it  is  best  suited.  The  machine  gun,  or  heavier  type, 
is  used  where  long-sustained  fire  of  any  kind  is  necessary^  as  for: 

(a)  Creating  bands,  or  belts,  of  fire  across  the  front  of  a  defensive 
position. 

(6)  Guarding  the  flanks  of  an  attack  by  covering  areas  of  ground 
with  ftre. 

(c)  Long  range  covering  fire. 

(d)  Indirect  fire,  etc. 

The  lighter,  or  Lewis  gun_tvpg.  has  generally  been  assigned  to 
Infantry  battalions  and  is  considered  ideal  for  supplementing^the 
lire  power  of  riflemen,  assisting  them  to  gain  lire  .superiority  and 
closely  supporting  thorn  on  all  occasions  in  either  attack  or  defense. 

The  ^ewjs  gun  type  is  the  first  to  go  forward  in  an  attacjfr  and  the 
last  to  be  brought  away  in  a  retirement.  This  type  enables  fewer 
of  the  machine-gun  type  to  be  placed  in  the  front  line  of  an  en- 
trenched position,  reduces  the  number  of  Infantry  in  the  front-line 
trenches,  and  enables  positions  won  in  an  attack  to  be  more  quickly 
organized. 

THE  UNITED  STATES  AUTOMATIC  MACHINE 
RIFLE.— The  Benet-Mercie  machine  rifle,  model  of  1909,  is  an 
extremely  light  weapon.  The  gun  alone  weighs  30  pounds,  or  just  a 
few  pounds  more  than  the  Lewis  gun,  and  it  can  be  used  in  the  f  ront- 
line  trenches  or  to  accompany  an  Infantry  line  with  the  same  facility 
that  theLewis  gun  is  used  for  these  purposes  in  Europe  at  present .  The 
Ordnance  Department  has  recently  modified  a  Vickers  tripod  for 
use  with  this  gun,  which  will  enable  it  to  be  used  in  the  support 
trenches  and  other  positions  in  rear,  as  are  the  Maxim,  Vickers, 
and  Colt  machine  guns  abroad.  The  tripod  weighs  45  pounds  and 
can  easily  be  carried  by  one  man  in  a  creeping  or  crawling  position 
over  all  kinds  of  ground. 


MACHINE   GUNS  IN  TRENCH  WARFARE.  7 

When  mounted  on  this  tripod,  the  Benet-Mercie  machine  rifle, 
model  of  1909",  can,  upon  occasion,  deliver  overhead  fire,  long  range, 
indirect,  and  searching  fire,  traversing  fire,  etc. 

In  other  words,  our  automatic  machine  rifle  can,  upon  occasion, 
play  the  r61es  of  the  six  types  or  two  classes  of  machine  rifles  in  use 
abroad. 

The  gun  has  a  case  for  protection  against  dirt  and  weather,  which 
weighs  about  16  pounds,  so  that  the  gun  in  its  case  weighing  about 
46  pounds,  and  the  modified  tripod  weighing  45  pounds,  can  each 
be  carried  by  a  single  man. 

As  the  War  Department  has  recently  adopted  the  Vickers  as  the 
heavy  type  machine  gun  for  the  United  States  Army,  it  is  unlikely 
that  the  Benet-Mercie  machine  rifle  will  be  called  upon  to  do  any 
work  except  that  to  which  it  is  best  suited. 

CHARACTERISTICS  OF  MACHINE  GUNS. 

(a)  Their  power  is  limited  to  fire  action. — Machine  guns  by 
fire  action  alone  can  pave  the  way  for  an  attack  or  ^rive  back  a 
hostile  assaujK  but  they  can  not  gain  ground.  The  latter  is  almost7 
exclusively  the  role;  of  Infantry,  which  is  capable  of  crossing  all 
obstacles.  Whenever,  therefore,  fire  action  alone  is  needed,  ma- 
chine guns  can  be  advantageously  employed  in  preference  to  In- 
fantry, the  latter  being  reserved  for  fire  action  combined  with~— ^ 
movement.  -  , 

(6)  Nature  of  fire. — Machine  gun  fire  ia  cnnpentrajjefj,;  therefore 
it  will  be  most  effective  against  a  narrow  and  deep  target.  As 
Infantry  normally  advances  in  extended  order,  the  best  means  of 
obtaining  the  above-mentioned  target  is  by  the  use  of  oblique  or 
enfilade  fire.  For  this  reason  flanking  fire  should  be  the  rule. 

Frontal  fire  should  only  be  used  against  troops  in  close  formations 
and  against  approaches,  such  as  roads,  bridges,  defiles,  communica- 
tion trenches,  etc.;  that  is  to  say,  against  places  where  the  enemy 
is  compelled  to  take  up  dense  formations  on  a  narrow  front.  The 
traversing  arrangement  allows  the  gun  to  be  turned  through  a  con- 
siderable angle  without  moving  the  tripod,  and  with  little  exposure. 

(c)  Invisibility. — Owing  to  its  small  frontage  it  is  easier  to  find  a 
concealed  position  for  a  machine  gun  than  for  an  equivalent  number 
of  riflemen.    Hence,  the  possibilities  of  surprise  effect  are  very 
great.    Surprise  is  essential  for  the  successful  handling  of  machine 
guns.    Flanking  fire  and  surprise  effect  should  always  be  sought  for. 

(d)  Mobility.— The  machine  gun  can  go  where  a  man  can  go  on 
foot. 


8  MACHINE  GUNS  IN  TRENCH  WARFARE. 

EMPLOYMENT. 

v 

The  general  principles  governing  the  employment  of  machine  guns 
are  exactly  the  same  in  either  open  fighting  or  trench  warfare,  but 
to  secure  maximum  results  from  the  guns  on  all  occasions  the  best 
method  of  applying  these  general  principles  to  the  peculiar  condi- 
tions of  the  present  war  must  be  studied. 

The  machine  gun  is  a  weapon  of  opportunity,  but  the  machine- 
gun  commander  must  not  passively  await  the  opportunity.  He 
must  keep  in  close  touch  with  the  situation  and  look  for  or  make  an 
opportunity  for  the  successful  employment  of  his  guns.  The  ma- 
chine-gun officer  must,  therefore,  be  alert  and  handle  his  guns  with 
boldness  and  cunning.  The  gunners  must  be  determined,  steady, 
and  full  of  resource  and  initiative. 

^COOPERATION. — Cooperation  is  essential,  not  only  between 

,-^lhe  machine  guns  of  a  single  organization,  but  between  those  and 

the  guns  of  adjacent  units.    Arrangements  must  be  made  for  cross 

fire  along  the  entire  front,  and  for  covering  spaces  not  reached,  or 

reached  with  difficulty,  by  artillery  fire. 

OPENING  FIRE. — The  general  rule  that  machine  guns  must 
not  open  fire  until  a  good  target  presents  itself  must  not  be  carried 
to  extremes,  otherwise  opportunities  for  the  infliction  of  both  moral 
and  actual  damage  upon  the  enemy  may  be  lost.  The  effect  likely 
to  be  produced  upon^the  enemy  is  Ihe  guiding^rjrinciple  which 
justifies  the  opening  of  fire.  It  is  often  impossible  to  see  anything 
"bFthe  enemy,  and  likely  positions  for  him  to  occupy  must  be  looked 
for  and  these  searched  with  fire,  if  necessary. 

Well-concealed  machine  guns  may  often  direct  their  fire  against: 

(1)  Windows,  doors,  and  roofs  of  houses  thought  to  be  occupied; 

(2)  areas  of  standing  crops  and  brush;  (3)  open  spaces  that  small 
parties  of  the  enemy  are  crossing;  and  (4)  the  enemy's  firing  line. 

NECESSITY  may  require  machine  guns  to  open  fire  upon  un- 
suitable targets  to  assist  the  advance  of  the  infantry,  or  to  open  fire 
in  self-defense. 

SURPRISE  EFFECT  should  always  be  the  aim  of  the  gun  com- 
mander. Unless  a  surprise  opening  of  fire  is  obtained,  the  gun  de- 
tachment, and  perhaps  the  gun  itself,  may  be  put  out  of  action 
before  any  effect  whatever  has  been  obtained. 

POST  OF  DETACHMENT.— As  few  men  as  possible  should  be 
around  the  gun.  Those  not  actually  necessary  to  work  the  gun 
should  be  engaged  in  the  ammunition  supply  or  under  cover. 

INTERVAL  BETWEEN  GTJNS.— If  liable  to  be  subjected  to 
artillery  fire,  the  interval  between  machine  guns  should  be  such 


MACHINE  GUNS  IN  TRENCH  WARFARE.       9 

that  no  two  guns  will  be  included  in  the  burst  of  a  single  shrapnel. 
This  interval  should  never  beJess  than  20  yards.  The  gun  positions 
should  be  such  that  the  guns  may  give  mutual  support  to  one  another 
by  means  of  cross  fire.  Positions  close  to  objects  whose  range  is 
known  to  the  enemy,  or  near  prominent  objects  that  will  aid  the 
enemy  in  finding  their  range,  are  to  be  avoided.  A  position  in  front 
of  a  dark  background,  or  in  ground  covered  with  a  suitable  growth 
that  will  hinder  observation,  should  be  sought.  During  an  advance 
or  a  retrograde  movement  the  guns  support  each  other  by  advanc- 
ing or  retiring  alternately,  as  the  case  may  be.  When 


infancy,  the  machine  gjms  should  mix  with  the  infantry  and  trv 

to  disguise  their  identity  as  much  as 


TINDER  ARTILLERY  FIRE.—  Great  care  must  be  taken  to 
prevent  the  machine  guns  from  being  located  by  the  artillery.  If 
guns  are  shelled,  they  must  change  position  at  once.  A  move  of  50 
yards  will  generally  be  sufficient,  f  hese  alternative  or  secondary 
j-ingjtjninH  will  always  be  select^  in  advance. 

It  may  sometimes  be  desirable  for  the  detachment  to  cease  firing 
and  to  retire  with  the  gun  under  cover  until  the  shelling  stops.  If 
this  is  done,  the  hostile  artillery  may  think  the  gun  has  been  put  out 
of  action.  When  good  targets  present  themselves,  the  machine  guns 
may  then  open  fire  again  from  the  same  position. 

AGAINST  ARTILLERY.  —  The  use  of  machine  guns  against 
artillery  is  exceptional.  The  following  cases  have  been  reported 
from  abroad: 

(a)  A  section  of  machine  guns  worked  forward  to  a  concealed  posi- 
tion 900  yards  from  a  field  battery  in  action,  and  bringing  oblique 
fire  against  the  battery,  completely  silenced  it. 

(6)  A  field  battery  in  action  was  taken  in  enfilade  by  a  machine- 
gun  section  at  2,400  yards.  The  gunners  fled  and  the  battery  was 
silenced. 

Frontal  fire  against  shielded  artillery  will  produce  moral  effect, 
which  should  be  considerable;  it  should  also  greatly  interfere  with 
the  supply  of  ammunition  to  the  guns. 

CARE  OF  MACHINE  GUNS.—  Every  lull  in  the  firing  should 
be  taken  advantage  of  to  clean  and  oil  the  gun.  Springs  should  be 
tested  and  the  gun  inspected  many  times  daily  'to  be  sure  that  it  is 
always  ready  to  respond  in  any  emergency.  The  ammunition  must 
be  kept  rhjaf^  When  not  in  use  the  gun  and  ammunition  should  be 
covered  with  waterproof  covers  to  protect  them  from  water,  dust. 
and  dirt. 


10  MACHINE   GUNS  IN  TRENCH  WARFARE. 

CONSIDERATIONS  GOVERNING  THE  PLACING  AND 
USE  OF  MACHINE  GUNS  IN  TRENCH  WARFARE  .—The 

answer  to  the  question,  "In  what  way  must  the  machine  guns 
at  my  disposal  be  placed  and  used  to- best  prevent  the  enemy  from 
capturing  these  trenches?"  will  decide  in  almost  every  case  how  the 
machine  guns  must  be  located,  distributed,  and  used. 

Unless  the  opposing  trenches  are  so  close  together  that  a  bombard- 
ment is  impossible,  an  offensive  with  the  object  of  breaking  our  line 
will  always  be  preceded  by  an  artillery  preparation.  The  object  of 
this  bombardment  will  be  to  destroy  the  wire  entanglements  and 
other  obstacles  in  front  of  our  trenches,  to  destroy  our  trenches, 
dug-outs,  artillery,  machine  guns,  personnel,  and  strong  points  in 
the  area  to  be  attacked,  and  to  prevent  our  reserves  from  being 
brought  forward. 

After  what  the  enemy  considers  a  suitable  artillery  preparation, 
his  grenadiers,  infantry,  and  machine  guns  will  move  forward  to  cap- 
ture our  trenches.  If  he  has  a  superiority  of  artillery  it  must  be 
expected  that  he  will  penetrate  our  line  in  places.  But  we  must  be 
prepared  to  receive  him  with  several  successive' belts  of  machine- 
gun  fire  that  will  delay  him  and  inflict  such  losses  upon  him  that  he 
will  be  forced  to  use  up  his  reserves  before  gaining  any  substantial 
advantages.  By  this  time  our  counterattack  should  b~e  able  to  drive 
him  back  with  heavy  losses. 

The  duties  of  the  machine  guns  of  the  defense  may  be  enumerated 
to  be: 

To  replace  as  many  riflemen  as  possible  in  the  actual  defense. 

To  prevent  the  enemy  from  leaving  his  trenches. 

To  sweep  all  ground  between  our  trenches  and  those  of  the  enemy. 

To  prevent  the  enemy  entering  our  trenches. 

To  isolate  portions  of  our  trenches  if  captured. 

To  sweep  communication  trenches  leading  from  our  front  trenches 
to  our  support  trenches. 

To  sweep  all  ground  between  our  support  line  and  front  line. 

To  provide  emergency  belts  of  fire  from  the  rear  to  replace  broken 
belts. 

To  engage  enemy  when  concentrating  for  assault. 

To  sweep  covered  approaches  to  enemy's  defensive  line. 

To  engage  enemy  machine  guns. 

To  sweep  ground  in  rear  of  the  enemy's  lines. 

To  provide  covering  fire  for  counterattacks. 

These  duties  and  the  necessity  for  cooperation  and  coordination 
of  effect  require  that  all  machine  guns  be  under  the  direction  of 
one  officer.  They  also  require  guns  to  be  distributed. 


MACHINE   GUNS  IN  TRENCH  WARFARE.  11 

In  or  near  the  front  line  trenches. 

In  or  near  the  support  trenches. 

In  positions  in  rear  along  communicating  trenches. 

In  strong  places  in  rear. 

In  reserve. 

The  number  of  guns  available  will  govern  the  decision  as  to 
whether  machine  guns  can  be  placed  in  all  of  these  positions  at 
one  time. 

Reports  from  the  present  European  war  indicate  that  several 
successive  lines  of  defence  are  not  to  be  aimed  at,  but  rather  a 
defended  area  whose  fortifications  are  laid  out  according  to  the 
nature  of  the  ground,  giving  machine  guns  freedom  of  position  that 
will  not  only  reduce  the  chance  of  their  being  knocked  out,  but 
will  also  reduce  to  a  minimum  the  number  required  to  form  any 
particular,  belt  or  band  of  fire. 

Reports  also  indicate  that  machine-gun  defence  schemes  must 
be  divisional,  in  order  to  make  these  belts  of  fire  continuous  and 
to  enable  the  construction  of  machine-gun  fieldworks  to  go  on  with- 
out interruption.  The  scheme  is  worked  out  so  as  to  hide  the 
machine  guns  from  enemy  artillery  and  protect  them  from  hostile 
bombers  and  snipers. 

LOCATION  AND  DISTRIBTJTION.— In  trench  warfare,  for 
the  reasons  given  above,  machine  guns  are  distributed  singly  along 
the  front  of  the  position  and  in  the  area  to  be  defended.  Some  of 
them  are  placed  in  the  firing  trenches,  some  in  emplacements 
between  these  trenches  and  the  wire  entanglements,  and  some 
behind  the  parados  just  in  rear  of  the  front-line  trenches.  The 
positions  of  those  in  the  firing  trenches  themselves  are  generally 
in  salients,  reentrants,  or  bends  in  the  trench  line.  Those  in  front 
of,  or  in  rear  of  the  trench  line,  are  generally  placed  in  front  of  or 
in  rear  of  a  traverse.  All  of  these  locations  are  positions  where 
they  can  best  cross  their  fire  for  mutual  support  and  where  they 
can  best  bring  an  enfilading  fire  against  an  advancing  infantry  line. 

Emplacements  in  front  of  the  firing  line  are  made  by  digging 
narrow  trenches  of  the  same  depth  as  the  firing  trench  to  the  front, 
15  or  20  feet,  and  then  turning  them  to  the  right  or  left  and  widen- 
ing them  out  to  accommodate  the  guns  and  crews.  The  gun  rests 
solidly  on  the  ground  at  the  end  of  this  cul  de  sac  which  is  sunk 
just  low  enough  below  the  natural  ground  to  conceal  it  when  in 
position. 

Some  machine  guns  are  placed  along  or  near  the  line  of  the  sup- 
port trenches,  a  short  distance  in  rear.  If  the  shape  of  the  ground 
permits,  these  are  so  placed  as  to  fire  over  the  heads  of  troops  in 


12  MACHINE   GUNS  IN  TRENCH  WARFARE. 

the  firing  trenches,  to  aid  in  repelling  an  attack,  also  to  bring  fire 
on  the  first-line  trenches  in  case  they  should  be  occupied  by  the 
enemy. 

Some  of  the  machine  guns  are  emplaced  along  the  communicat- 
ing trenches  and  some  around  a  strong  point,  200  or  300  yards  in 
rear  of  the  front-line  trenches,  in  such  a  way  as  to  stop  the  enemy 
should  he  be  able  to  capture  the  first  line  and  support  trenches, 
and  to  hold  him  until  a  counterattack  can  be  delivered. 

TJie  remainder  of  the  machine  guns  are  held  in  reserve,  to  replace 
casualties,  or  for  use  where  the  commander  may  decide  and  for 
instructional  purposes.  Plates  1,  2,  3,  and  4  show  the  location  of 
machine-gun  emplacements  and  the  methods  of  obtaining  enfilade, 
covering,  and  cross-fire  along  three  different  fronts  in  Europe. 
Plates  5  and  6  show  some  details  of  the  position  shown  in  Plate  1. 

EMPLACEMENTS. — In  positions  in  the  line  where  one. can  be 
heavily  bombarded,  machine  guns,  or  at  any  rate  some  of  them, 
should  be  kept  under  cover  day  and  night,  but  in  those  portions 
of  the  line  where  the  enemy  is  so  close  that  a  bombardment  is 
impossible  and  our  only  fear  is  a  sudden  rush,  machine  guns  should 
be  mounted  in  position  ready  loaded,  always  at  night,  and  also 
during  the  daytime  when  the  entanglements  will  not  give  sufficient 
time  for  them  to  get  ready. 

The  number  of  emplacements  constructed  must  generally  be 
greater  than  the  number  of  machine  guns  assigned  to  the  protected 
area,  for  guns  which  come  under  artillery  fire  must  have  an  alterna- 
tive or  secondary  position  and  there  must  be  emplacements  for  the 
machine  guns  in  reserve  and  there  must  also  be  emplacements  in 
reserve  to  take  the  place  of  those  destroyed  by  the  artillery  bom- 
bardment. 

The  enemy's  bombardment  of  our  front  line  must  cease  when  his 
infantry  arrives  within  about  200  yards  of  it,  but  it  will  increase  in 
intensity  against  the  trenches  in  rear,  in  order  to  prevent  the  infantry 
and  machine  guns  in  those  trenches  from  participating  in  the  defense. 
It  follows,  therefore,  that  our  machine  guns  must  be  numerous  enough 
along  the  front  line  and  sufficiently  strongly  emplaced,  so  that 
enough  of  them  will  survive  the  bombardment  and  appear  as  soon 
as  the  artillery  cone  lifts  and  open  fire  on  our  wire  entanglements  and 
the  ground  in  front  of  it. 

Owing  to  the  extent  of  front  attacked  and  to  the  difficulty  of 
artillery  observation,  it  is  unlikely  that  an  entire  front-line  system 
of  trenches  and  machine-gun  emplacements  will  be  entirely  pulver- 
ized by  any  artillery  bombardment.  The  experience  in  Europe  has 
been  that  some  machine  guns  and  crews  have  always  survived,  ready 


MACHINE  GUNS  IN  TRENCH  WARFARE.  13 

to  emerge  and  open  a  flanking,  annihilating  fire  against  the  enemy's 
advancing  infantry  and  the  more  oblique  has  been  this  cross  fire  the 
greater  has  been  its  effect. 

The  emplacing  of  guns  for  cross  fire,  however,  must  not  be  be 
carried  to  the  extreme.  While  the  front  of  each  gun  is  supposed  to 
be  protected  by  the  cross  fire  of  its  neighbor,  if  the  neighbor  should 
meet  with  mishap  or  should  be  under  artillery  fire  and  unable  to 
perform  its  function,  fire  to  the  front  must  be  arranged  for  by  the 
gun  itself. 

Where  opposing  trenches  are  close  together  and  machine  guns 
would  be  subject  to  capture  by  raid  if  placed  in  the  front-line  trench 
or  in  front  of  it,  this  danger  can  be  avoided  by  emplacing  them 
behind  the  parados  of  the  firing  trench.  This  position  will  give  a 
better  field  of  fire,  and,  owing  to  the  feeling  of  safety  which  this 
position  inspires,  the  men  will  work  their  gun  with  more  coolness 
and  judgment  than  if  the  gun  were  sited  in  the  parapet  or  in  front 
of  it. 

Plate  12  shows  such  a  gun  position  connected  by  an  underground 
passage  to  an  ordinary  infantry  dugout,  situated  under  the  parapet. 
In  this  dugout  underground  cover  is  provided  for  the  machine  gun, 
its  crew,  as  well  as  for  the  infantry  squad  pertaining  to  that  trench. 
The  dugout  is  also  connected  with  the  firing  trench.  Should  the  in- 
fantry squad  be  driven  from  the  firing  trench,  or  should  this  trench 
be  destroyed,  they  will- take  post  behind  the  parados  on  the  flanks  of 
the  machine  gun. 

Plates  7,  8,  9,  10,  and  11  show  some  types  of  open  and  protected 
machine-gun  emplacements  that  have  been  used  in  the  present  war. 
If  time  and  materials  are  available,  some  of  the  emplacements  and 
dugouts  near  the  front  line  must  be  made  strong  enough  to  resist  the 
heaviest  bombardment. 

It  must  be  remembered  that  the  stubborn  defense  of  the  front 
trenches  will  often  depend  on  the  machine  guns,  and  that  although 
the  rifle  garrison  may  sometimes  be  withdrawn  to  their  bomb  proofs 
and  dugouts,  the  machine  gunners  must  remain  at  their  posts.  There- 
fore, the  machine  guns  and  their  personnel  must  have  dugouts  and 
emplacements  that  will  survive  the  bombardment. 

The  general  experience  of  the  effect  of  intensive  bombardment  on 
front-line  trenches,  when  well  carried  out,  has  been  that  large  por- 
tions of  the  parapet  have  ceased  to  exist ;  and  that  unless  machine-gun 
emplacements  in  the  parapet  are  dug  at  ground  level  and  covered 
by  heavy  beams,  heavily  supported,  they  will  be  destroyed  at  tho 
same  time.  A  system  of  strong  dugouts  behind  the  parados  in  which 


14  MACHINE   GUNS  IN  TRENCH  WARFARE. 

most  of  the  machine  guns  can  be  kept  safely  during  bombardment, 
will  make  them  available  when  the  bombardment  is  over. 

In  connection  with  the  emplacements  there  must  be  ample  pro- 
tection for  look-out  men,  who  are  detailed  to  give  the  signal  for  the 
mounting  of  the  machine  guns  as  soon  as  the  artillery  cones  lift. 
It  is  reported  that  concrete  emplacements  and  dugouts  have  been 
constructed  at  many  important  po'nts  on  the  present  trench  line 
in  Europe. 

Dugouts  can  be  made  by  tunneling  deep  down  under  the  parapet 
or  parados,  or  by  building  shelter  in  a  traverse. 

Plenty  of  earth,  well  supported  by  timber  and  inconspicuous  from 
the  front,  is  the  aim  in  their  construction.  Machine-gun  dugouts 
should  be  near  the  gun  emplacements,  and  it  seems  to  be  the  practice 
to  build  two  dugouts  for  each  gun.  Into  these  are  carried  the  gun, 
spare  parts,  and  ammunition  during  a  bombardment  when  the 
emplacements  are  too  weak  to  remain  in  them. 

Emplacements  should  be  constructed  to  look  like  the  remainder 
of  the  trench  and  loopholes  should  be  masked. 

The  simplest  form  of  emplacement  is  a  semicircular  pit  about  2 
feet  deep  with  sand-bag  revetment.  Emplacements  are  numbered 
from  right  to  left  in  any  given  section. 

Plate  12  shows  a  simple  type  of  machine-gun  loophole. 

Plate  13  is  a  type  used  for  night  firing. 

The  simplest  form  is  an  arrangement  whereby  a  steel  shield  and 
one  or  more  sandbags  can  be  removed  from  the  revetment. 

The  machine  guns  in  the  strong  points  should  be  emplaced  to  fire 
in  all  directions.  The  emplacement  should  be  very  strong,  with 
dugouts,  overhead  cover,  and  ammunition  depots,  all  protected  by 
snipers  and  bombers,  and  the  whole  surrounded  by  wire. 

DIMENSIONS  OF  EMPLACEMENTS,  DUGOUTS,  AND 
LOOPHOLES. — Dugouts  and  emplacements  are  made  as  small  aa 
possible.  The  least  dimension  for  a  dugout  for  4  men  will  be  found 
to  be  about  6  by  5  by  4  feet.  Minimum  dimensions  of  emplacements 
are  about  the  same,  though  a  minimum  of  5  by  4  by  4  feet  is  reported 
to  be  in  use  for  both  of  these  in  the  present  European  trenches. 

The  firing  platform  must  be  from  18  to  24  inches  below  the  height 
over  which  the  gun  is  to  fire. 

The  loophole  is  generally  9  inches  high  by  a  dimension  deter- 
mined by  the  thickness  of  the  parapet  and  the  number  of  degrees 
of  traverse  desired. 

MATERIALS. — A  loophole  box  is  easily  made  of  2-inch  plank. 
Sleepers  of  6  by  4  inch  material  for  roofing  and  upright  posts  of 


MACHINE   GUNS  IN  TRENCH  WARFARE.  15 

7  by  4  inch  dimensions  will  be  found  strong  enough  to  use  in  emplace- 
ments and  dugouts.  Corrugated  iron  shegts  may  be  used  to  cover 
the  roof.  Some  nails  will  be  needed,  also  sandbags  and  close  mesh 
wire  netting  for  revetting. 

Protection  from  rifle  fire,  shrapnel,  and  splinters  from  shells, 
bombs,  and  small  high  explosive  shell  from  field  guns,  will  generally 
be  obtained  by  a  parapet  of  earth  6J  or  7  feet  thick.  Open  emplace- 
ments should  have  this  thickness  of  earth  in  front  of  them.  Covered 
emplacements  will  be  splinter  proof  if  there  is  20  inches  of  earth  on 
top. 

AMMUNITION. — An  ammunition  chamber  must  be  prepared 
in  each  emplacement.  In  this  is  kept  sufficient  ammunition  for 
immediate  needs,  a  box  of  spare  parts  for  the  gun,  oil,  and  cleaning 
materials. 

All  alternative  emplacements  have  these  chambers  fully  equipped 
so  that  they  may  be  occupied  at  a  moment's  notice  if  the  regular 
emplacement  has  to  be  abandoned.  Ammunition  supply  must  be 
carefully  thought  out.  Reserve  ammunition  in  unopened  boxes 
and  arrangements  for  refilling  empty  strips  or  belts  and  making 
repairs  are  located,  with"  spare  gunners,  at  a  central  dugout.  Arrange- 
ments must  be  made  to  keep  ammunition  clean,  and  dry.  It  should 
be  inspected  daily. 

RANGE  CARDS. — Cards  are  prepared  for  each  emplacement 
and  alternative  emplacement,  giving  reference  point  and  ranges 
to  all  probable  targets  and  to  prominent  objects.  These  are  left 
in  the  emplacement  day  and  night,  whether  occupied  or  not.  Plate 
14  shows  a  form  used  abroad. 

QENERAL  REMARKS. 

To  reduce  losses  during  bombardments,  when  there  is  danger  of  a 
machine  gun  being  struck,  it  is  usual  to  dismount  it,  wrap  in  a  water- 
proof covering,  and  remove  it  to  a  safe  place,  leaving  the  tripod  in 
place  so  that  the  gun  can  be  quickly  mounted  in  case  of  emergency. 
If  no  safe  place  is  available,  the  gun  is  put  in  the  bottom  of  the 
trench,  the  waterproof  covering  preventing  its  becoming  clogged  if 
buried  by  shell  fire.  Gunners  should  not  retire  to  the  same  dugout 
or  to  the  same  part  of  trench.  After  bombardment  two  men  mount 
the  gun,  the  remainder  of  the  personnel  remaining  under  cover, 
unless  the  signal  of  enemy  attack  is  given,  when,  of  course,  no 
attention  is  paid  to  this  precaution.  As  few  men  of  the  gun  crew  as 
possible,  generally  3  or  4,  remain  in  the  front  trenches,  the  others 
remain  in  dugouts  and  reserve  trenches  in  rear; 


16  MACHINE   GUNS  IN  TRENCH  WARFARE. 

One  emplacement  is  iisually  reserved  for  each  gun  as  a  "Battle 
emplacement,"  to  be  used  only  in  case  of  enemy  attack.  Alter- 
native and  dummy  emplacements  are  used  from  day  to  day  for  firing 
at  such  targets  as  present  themselves.  A  few  rounds  from  these 
will  deceive  the  enemy  as  to  the  location  of  best  emplacements,  as 
well  as  the  number  of  guns  along  the  line.  Emplacements  and  dug- 
outs must  be  kept  in  good  repair.  Sandbags,  chicken  wire,  and  stakes 
are  freely  used  in  repairs. 

In  each  emplacement  the  limits  that  the  machine  gun  can  with 
safety  be  traversed  without  endangering  friendly  troops  should  be 
clearly  marked  by  posts,  stakes,  or  sandbags,  arranged  so  as  to  make 
traversing  beyond  these  limits  impossible. 

OVERHEAD  FIRE. — Whenever  machine  guns  are  going  to  fire 
over  our  own  trenches,  the  occupants  of  the  trenches  must  be  in- 
formed. 

LAYING  OUT  TRENCHES.— When  entrenchments  are  dug 
deliberately,  they  should  be  laid  out  with  a  view  to  defense  by 
machine  guns.  The  machine-gun  positions  should  first  be  chosen 
and  the  trenches  laid  out  accordingly,  thus  enabling  the  trenches 
to  be  held  by  machine  guns,  supported  by  a  minimum  number  of 
riflemen. 

POST  OF  MACHINE-GUN  COMMANDER.— The  commander 
must  locate  himself  centrally  so  that  messages  may  readily  reach 
him,  and  so  that  he  can  coordinate  the  work  of  all  the  guns  of  his 
command  according  to  the  plan  of  the  commander  of  the  troops. 
He  must  have  at  hand  orderlies  and  signal  men  well  trained  in 
maintaining  communication  with  the  different  gun  positions. 

EQUALIZING  DUTIES. — To  give  men  and  officers  of  machine- 
gun  organizations  sufficient  rest,  a  regular  roster  should  be  kept. 
As  only  three  or  four  men  are  needed  with  the  gun  in  the  front  line 
at  any  one  time,  the  remainder  of  the  crew  should  be  allowed  to 
remain  in  reserve  in  the  reserve  trenches  or  reserve  dugouts.  This 
will  enable  men  in  the  front  line  trenches  to  be  relieved  every  24 
hours.  Organizations  should  be  relieved  as  often  as  possible. 

PERISCOPES. — Periscopes  should  not  be  used  from  machine- 
gun  position,  but  to  one  side  of  them. 

ILLUMINANTS. — Each  machine  gun  in  the  front  line  should 
have  a  Very  pistol,  or  some  other  illuminant  to  show  up  enemy  night 
attacks  and  enable  fire  to  be  directed  on  them. 

SNIPERS  AND  BOMBERS. — When  opposing  trenches  are 
close  together,  bombers  and  snipers  should  be  detailed  to  protect 
the  flanks  of  machine-gun  positions. 


MACHINE   GUNS  IN  TRENCH  WARFARE.  17 

Also  during  an  attack,  the  machine  guns  will  be  worked  to  better 
advantage  if  a  few  men  are  assigned  to  their  protection  from  bombing 
attacks  of  the  enemy. 

ENEMY  MACHINE  GUNS.— When  contemplating  an  attack, 
if  enemy  machine  guns  are  located,  and  they  are  not  doing  any  ma- 
terial damage,  it  may  be  advisable  to  leave  them  alone,  instead  of 
firing  at  them  and  making  them  change  their  positions.  Then, 
when  our  attack  is  launched,  the  guns  may  be  in  the  same  position 
and  our  guns  may  be  able  to  keep  them  from  firing  on  our  troops. 

OBSERVATION. — Officers,  noncommissioned  officers,  and  all 
men  of  maching-gun  units  must  be  well  trained  in  the  use  of  the 
telescope,  both  for  observation,  of  fire  and  in  picking  up  the  enemy's 
machine  guns.  This  requires  constant  practice. 

CONCEALMENT. — Concealment  must  be  aimed  at  in  every 
case.  Emplacements  are  made  to  look  like  the  surrounding  ground, 
so  as  not  to  attract  the  attention  of  enemy  observing  parties.  Saps 
leading  to  emplacements  are  covered  with  canvas,  brushwood,  straw, 
sandbags,  etc.,  to  prevent  photographic  location  by  aircraft.  The 
coverings  can  be  easily  removed  if  necessary. 

ORDERS. — Owing  to  the  fact  that  the  immediate  gun  detach- 
ments change  each  24  hours  and  organizations  are  relieved  from 
trench  duty  frequently,  it  has  been  found  necessary  in  the  present 
trench  warfare  in  Europe  to  have  the  orders  for  each  gun  detach- 
ment posted  in  the  gun  position  so  mistakes  will  not  occur. 

These  orders  prescribe  among  other  things: 

1.  That  when  detachments  change,  the  piece  shall  be  inspected 
that  the  points  shown  on  the  range  card  be  pointed  out  carefully 
and  that  report  be  made  whether  the  gun  has  been  fired  during  the 
preceding  relief;  if  so,  at  what  target,  and  from  which  emplacement. 

2.  That  fire  is  to  be  opened  only  by  order  of  the  gun  commander, 
except  in  a  sudden  emergency. 

3.  That  the  gun,  ammunition,  and  spare  parts  shall  be  cleaned 
and  oiled  daily. 

4.  Hours  when  gun  will  be  mounted  in  emplacement. 

5.  Other  rules  necessary  for  the  particular  emplacement  and  the 
care  of  the  gun. 

USE  OF  MACHINE  GUNS  IN  THE  DEFENSE  IN 
TRENCH  WARFARE. — It  has  been  previously  stated  that  when 
machine  guns  are  placed  for  the  defense  of  an  entrenched  line, 
the  guns  of  each  section  of  the  line  must  be  arranged  under  the 
direction  of  one  officer.  This  officer  will  be  the  machine-gun  officer 
of  a  brigade,  under  the  supervision  of  the  division  machine-gun 
«— 17 — 2 


18  MACHINE   GUNS  IN  TRENCH  WARFARE. 

officer,  for  the  reasons  stated.  Under  hie  direction,  areas  to  be 
covered  are  allotted  to  each  machine  gun.  These  areas  should 
slightly  overlap. 

In  allotting  these  areas,  care  must  be  taken  that  the  whole  of  the 
area  can  actually  be  seen  by  the  man  firing  the  particular  gun.  The 
mere  marking  out  of  theoretical  areas  of  fire  on  a  map  is  not  sufficient. 
It  is  the  custom  abroad  to  prepare  a  trench  map  showing  the  position 
of  the  machine  guns  and  the  areas  covered  by  each. 

Machine-gun  officers  of  adjacent  brigades  must  confer  together  as 
to  the  placing  of  their  flank  guns,  in  order  to  insure  that  all  ground 
in  front  of  the  intrenched  line  can  be  and  will  be  swept.  The 
machine-gun  officer  also  studies  the  enemy's  advanced  trenches  and 
finds  out  those  portions  that  can  not  be  reached  by  our  artillery,  or 
that  can  be  reached  only  with  difficulty,  and  arranges  his  machine 
guns  so  as  to  bring  enfilade  or  oblique  fire  upon  them.  Fulfilling 
all  of  these  conditions  his  aim  will  be  to  locate  his  guns  so  as  to  create 
several  successive  belts  of  machine-gun  fire  and  to  place  his  machine 
guns  so  as  to  bring  enfilade  or  oblique  fire  against  the  enemy's 
trenches,  the  ground  over  which  the  enemy  must  pass  should  he 
attack,  and  against  our  own  front  line  trenches  should  the  enemy 
succeed  in  entering  them. 

As  previously  stated,  these  objects  will  generally  be  achieved  by 
placing  the  guns  either  in  front  of  the  trench,  in  a  bend  of  the  trench, 
in  a  salient,  in  a  reentrant,  or  in  or  near  support  and  communication 
trenches. 

The  machine  guns  should  always,  if  possible,  be  covered  from  fire 
from  the  front,  while  themselves  being  able  to  sweep  the  front  of  the 
intrenched  line  with  cross  fire.  The  front  of  each  gun  is  swept  by 
the  fire  of  its  neighboring  machine  gun,  but  in  cases  of  emergency, 
all  guns  must  have  arrangements  for  firing  to  their  own  front. 

Some  sandbags  can  be  removed  and  the  machine  gun  can  be  fired 
to  the  front  through  the  loophole  thus  made,  or  the  gun  can  be 
quickly  removed  from  the  tripod,  if  mounted,  and  fired  over  the 
parapet  without  it,  or  it  may  be  fired  from  some  other  position  pre- 
viously selected. 

DISTRIBUTION  OF  THE  MACHINE  GUNS.— The  shape  of 
the  ground  will  determine  the  distribution  of  the  machine  guns  to  a 
great  extent.  As  a  general  rule  some  of  the  machine  guns  will  be 
placed  in  or  near  the  front  line  of  trenches,  for  if  it  is  intended  to 
defend  the  front  line  obstinately,  the  machine  guns  may  just  make 
the  difference  between  success  and  failure.  Some  will  usually  be 
placed  in  or  near  the  support  trenches  to  prevent  the  further  advance 
of  the  enemy  should  he  be  able  to  enter  the  front  line  trenches. 


MACHINE   GUNS  IN  TRENCH  WARFARE.  19 

If  the  ground  is  favorable  some  will  be  placed  in  concealed  posi- 
tions in  rear  and  arrangements  made  to  fire  over  our  trenches  and 
sweep  the  ground  in  front  of  them,  to  fire  through  gaps  in  oiir  line, 
to  cover  positions  from  which  the  enemy  might  prepare  for  an  assault, 
to  bring  fire  upon  positions  likely  to  be  occupied  by  enemy  machine 
guns,  to  assist  our  own  troops  to  assault  by  protecting  their  flanks, 
and  by  overhead  covering  fire,  and  to  use  indirect  fire  against  ground 
in  rear  of  the  enemy's  lines. 

Some  will,  if  possible,  be  placed  in  strong  points  farther  to  the 
rear,  that  must  hold  out  till  a  counterstroke  can  be  delivered. 

Any  remaining  guns  are  held  in  reserve  to  replace  those  disabled, 
to  reinforce  threatened  points,  and  for  instructional  purposes. 

If  there  are  not  enough  machine  guns  for  all  of  these  positions  at 
one  time,  emplacements  should  at  least  be  prepared  in  all  of  them 
and  arrangements  made  so  that  machine  guns  may  be  quickly  placed 
in  any  of  these  emplacements,  when  required. 

Arrangements  are  also  made  for  rapid  communication  between  all 
parts  of  the  machine-gun  defense  area,  and  a  quick  ammunition 
supply  system  worked  out. 

The  brigade  machine-gun  officer  must  know  the  brigade  com- 
mander's plans  and  he  must  work  out '  the  whole  machine-gun 
defense  scheme,  so  as  to  coordinate  the  use  of  his  guns  with  these 
plans.  His  post  must  be  near  that  of  the  brigade  commander,  or  in 
such  a  position  that  he  can  easily  communicate  with  him. 

USE  OF  MACHINE  GUNS  IN  THE  ATTACK.— It  has  been 
found  that  continuous  trench  service  impairs  the  offensive  spirit  of 
troops;  so  now  when  an  attack  is  contemplated,  fresh  troops,  who 
have  not  recently  served  in  the  trenches,  are  brought  forward  to 
make  it.  These  are  selected  troops  of  best  training  and  highest 
morale.  Aeroplane  maps  of  the  front  to  be  attacked  are  obtained 
and  carefully  studied.  Besides  distributing  guns  of  different  cali- 
bers along  the  front  and  collecting  large  quantities  of  ammunition 
for  use  during  the  artillery  preparation,  the  infantry  and  machine 
guns  are  carefully  instructed  as  to  their  tasks.  The  machine  guns 
must  be  used  in  such  a  manner  as  to  best  aid  the  infantry.  The 
brigade  machine-gun  officer  must  have  full  knowledge  of  the  pkn  of 
operations  at  the  earliest  possible  moment,  so  that  he  can  make 
detailed  plans  for  the  machine  guns  of  the  whole  brigade.  These 
plans  will  be  made  in  consultation  with  the  brigade  commander, 
who  will,  after  approval,  issue  the  necessary  orders  for  carrying  out 
their  part  of  the  plan. 


20  MACHINE   GUNS  IN  TRENCH  WARFARE. 

In  making  his  detailed  plan  for  the  use  of  the  machine  guns  of  the 
brigade,  the  brigade  machine-gun  officer  must  make  a  careful  study 
of  the  enemy's  front  line  and  its^relation  to  his  own  trenches.  He 
must  also  study  the  ground  in  rear  of  the  enemy's  front  line,  which 
he  will  be  able  to  do  from  the  aeroplane  maps. 

Machine  guns  are  the  weapons  most  likely  to  hold  up  an  attack, 
and  every  effort  must  be  made  to  locate  enemy's  machine  guns,  in 
order  that  some  of  our  machine  guns  may  be  detailed  in  pairs,  if 
possible,  to  engage  them  immediately  the  bombardment  ceases. 

After  studying  the  situation  in  connection  with  the  brigade  com- 
mander's plan,  the  brigade  machine  gun  officer  then  divides  up  his 
guns  and  gives  them  the  individual  tasks  that  will  coordinate  the 
whole  scheme.  He  must  make  sure  that  the  machine  gun  positions 
that  he  will  use  at  the  beginning  of  the  attack  are  in  good  condition, 
well  supplied  with  ammunition,  and  that  all  arrangements  have  been 
made  for  rapid  communication. 

In  this  manner  each  machine  gun,  or  group  of  machine  guns,  will 
have  a  specific  task  allotted  to  it,  and  before  the  action  commences, 
all  concerned  will  thoroughly  understand  their  duties  and  the  par- 
ticular part  that  they  are  to  play  in  the  attack. 

All  machine  guns  must  be  in  their  allotted  places  and  ready  for 
action  by  the  time  the  artillery  bombardment  commences. 

THE  ALLOTMENT. 

.  1.  Some  to  go  forward  with  the  attacking  Infantry. — The 
number  to  go  forward  with  the  Infantry  will  be  determined  by  the 
nature  of  the  enemy's  trenches,  the  length  of  the  line  to  be  attacked, 
and  the  number  of  machine  guns  available.  These  machine  guns 
will  go  forward  with  the  fourth  wave  of  the  attacking  Infantry, 
mingling  with  the  Infantry  so  as  to  make  an  inconspicuous  target. 
These  guns  will,  at  first,  use  the  light  muzzle  tripod.  The  heavy 
tripod  will  be  brought  forward  after  the  Infantry  is  secure  in  the 
trenches  that  it  is  to  capture. 

These  machine  guns  hold  themselves  ready  to  go  forward  at  the 
earliest  moment  and  should  not  open  fire  until  they  reach  the  ad- 
vanced position. 

Their  role  will  be  to  make  good  against  a  counterattack,  the  ground 
gained  by  the  Infantry,  and  the  approximate  locality  in  which  they 
will  be  mounted  in  the  captured  line  should  be  settled  before  the 
advance  begins. 

2.  Some  to  cover  the  Infantry  advance. — The  positions  that 
these  machine  guns  will  take  will  depend  upon  the  configuration 


MACHINE   GUNS  IN  TRENCH  WARFARE.  21 

of  the  ground  and  the  position  of  the  enemy  trenches  in  relation  to 
our  own,  as  well  as  the  nature  of  the  attack. 

Their  r61e  is  to  deliver  a  covering  and  flanking  fire.  In  playing 
this  role  some  of  the  machine  guns  will  be  placed  to  prevent  the  cross 
fire  by  rifles  and  machine  guns  from  the  enemy  trenches,  situated 
on  the  flanks  of  the  attack;  some  to  bring  oblique  and  enfilade  fire  on 
the  part  of  the  enemy  trenches  to  be  attacked ;  and  some  to  sweep  the 
ground  over  which  enemy  reserves  must  move  to  the  counterattack; 
some  machine  guns  may  be  pushed  out  to  the  front  through  saps 
previously  prepared  to  keep  down  the  enemy's  fire  while  our  Infan- 
try is  getting  out  of  the  trenches  and  through  the  wire  entangle- 
ments. 

All  covering  machine  gun  crews  should  be  instructed  that  when 
our  Infantry  masks  the  fire  of  their  guns,  they  should,  if  possible, 
direct  their  fire  past  the  flanks  of  the  attacking  Infantry,  in  order  to 
keep  down  flanking  fire  and  to  prevent  flank  attacks;  also,  if  our 
troops  are  forced  to  lie  down  between  the  trenches,  that  these  ma- 
chine guns  must  try  to  keep  down  the  fire  of  the  enemy's  rifles  and 
machine  guns. 

It  must  be  understood  L  all  commanders,  that  each  machine  gun 
has  been  given  a  specific  task  in  a  concerted  plan  and  that  the 
machine  guns  must  not  be  interfered  with  or  their  orders  changed 
by  any  one  except  the  machine-gun  commander  or  the  commander 
of  the  brigade. 

3.  Some  in  reserve  under  the  brigade  commander. — These 
machine  guns  will  constitute  a  real  reserve  and  will  not  be  pushed 
into  the  fight  too  early.  From  positions  in  rear  they  can  aid  the 
attack  by  sweeping  ground  behind  the  enemy  front  line  and  by  firing 
against  counterattacks.  Indirect  fire  may  be  used  in  these  cases,  if 
necessary. 

Cases  have  been  reported  where  machine  guns  have  been  used 
to  ajd  the  artillery  preparation  by  firing  upon  and  helping  to  destroy 
the  wire  entanglements.  Such  a  use  was  effective,  but  the  ex- 
penditure of  ammunition  was  not  commensurate  with  results  pro- 
duced. 

AMMUNITION  SUPPLY.— An  officer  should  be  placed  in 
charge  of  the  ammunition  supply,  and  all  arrangements  should  be 
carefully  made  for  depots  and  supply  before  the  action  begins. 

COMMUNICATION.— The  brigade  machine-gun  officer,  as  a 
rule,  remains  near  the  brigade  commander.  He  will  prepare  for 
communication  with  all  machine  guns,  or  groups  of  guns,  by  the  usual 
means,  as  well  as  by  having  ft  sufficient  number  of  orderlies  on  hand 


22  MACHINE  GUNS  IN  TRENCH  WARFARE. 

for  this  purpose  should  the  usual  means  of  communication  become 
disarranged. 

SUCCEEDING  PHASES.— If  the  attack  is  to  consist  of  more 
than  one  phase,  a  separate  plan  must  be  made  for  each  advance. 

METHOD  OF  GIVING  ORDERS  AND  ALLOTTING 
TASKS. — Reports  indicate  that  "before  an  attack  the  brigade 
machine-gun  officer  assembles  all  officers  and  senior  noncommissioned 
officers  of  the  brigade  machine  gun  units,  and  with  the  aeroplane 
maps  of  the  enemy's  trenches  and  the  defended  area  to  be  attacked 
before  him,  he  explains  to  them  the  plan  of  attack,  allots  the  different 
tasks,  and  designates  the  position  to  be  taken  by  each  gun  before  the 
beginning  of  the  attack  and  the  point  of  the  enemy's  trench  to 
which  each  will  advance  during  the  forward  movement,  announces 
the  location  of  the  ammunition  depot,  the  name  of  the  officer  charged 
with  ammunition  supply,  arrangements  for  communication,  his 
position,  and  gives  any  other  orders  pertaining  to  the  special  case 
that  may  be  necessary. 

LATE  REPORTS. — Reports  received  since  this  paper  was 
written  state  that  machine  guns  are  now  being  manufactured  in 
sufficient  quantities  to  enable  the  Allies  to  make  full  use  of  them  on 
the  western  front. 

One  report  states  that  a  machine  gun  company  with  8  guns,  of  the 
heavy  type,  has  recently  been  added  to  each  infantry  battalion  of  a 
certain  power,  and  that  additional  companies,  belonging  to  "a 
machine  gun  corps,"  are  being  formed. 

These  latter  companies  are  handled  in  a  manner  similar  to  the 
artillery  of  the  army,  that  is,  they  are  assigned  to  special  sectors 
according  to  contemplated  operations  and  to  the  necessity  for 
machine  guns.  These  guns  are  all  of  the  heavy  type  and  are  said 
to  be  in  the  proportion  of  13  to  every  1,000  infantry  rifles. 

The  report  further  states  that  every  infantry  company  has  16  auto- 
matic rifles,  weighing  18  pounds  each.  The  power  referred  to  seems 
to  use  this  automatic  rifle  in  the  front  line  trenches  as  a  substitute 
for  the  Lewis  type  gun.  This  automatic  rifle  is  reported  to  use  a 
magazine  clip  holding  20  cartridges,  to  fire  at  the  rate  of  150  rounds 
per  minute,  and  to  be  quite  accurate  up  to  600  yards,  beyond  which 
range  the  machine  gun  is  used. 

EFFECT  OF  GAS  ON  MACHINE  GUNS.— The  effect  of  gaa 
upon  machine  guns  and  cartridges  and  the  method  of  employing  the 
guns  during  a  gas  attack  are  given  in  the  Synopsis  of  Principles  at 
the  end  of  this  pamphlet. 


MACHINE   GUNS  IN  TRENCH  WARFARE.  23 

TRAINING  OF  MACHINE-GUN  UNITS. 

Most  of  the  belligerents  abroad  now  have  "machine-gun  training 
centers  "  to  which  officers  and  men  selected  for  machine-gun  service 
are  sent  for  several  weeks  of  intensive  training  before  being  for- 
warded to  their  organizations. 

£ome  of  these  centers  have  facilities  ior  training  several  thousand 
men,  and  they  keep  up  a  steady  flow  of  trained  men  toward  the  front. 
Besides  large  target  ranges,  with  which  all  centers  are  provided, 
there  are  at  these  centers  facilities  for  training  the  personnel  in 
grenade  throwing,  in  signaling,  and  for"  giving  necessary  instruc- 
tion in  riding  and  in  the  care  of  animals. 

The  sending  of  officers  and  men  to  these  centers  enables  them  to 
receive  training  from  selected  instructors,  insures  a  uniform  system 
throughout  the  service,  and,  as  machine-gun  officers  invalided  from 
the  front  are  sent  to  these  centers  for  light  duty,  the  instruction  is 
kept  up  to  date. 

'  SELECTION  OF  PERSONNEL.— In  order  to  have  a  depend- 
able machine-gun  force  which  can  obtain  the  best  results  from  the 
guns,  a  highly  trained  personnel  is  necessary.  Officers  and  men 
must  know  their  gun  thoroughly.  They  must  understand  both  the 
theoretical  and  practical  sides  of  machine-gun  employment,  as  well 
as  the  theory  of  machine-gun  fire  and  of  trajectories  of  bullets  at  the 
different  ranges.  The  personnel  should  be  carefully  selected.  The 
officers  must  be  intelligent,  resourceful,  bold,  and  must  have  good 
judgment.  The  work  is  hard,  so  the  men  must  have  superior 
physique.  They  should  be  able  to  run  or  crawl  from  position  to 
position  carrying  gun,  tripod,  or  ammunition.  Those  unable  to  do 
this  or  without  staying  qualities  should  be  transferred.  They  must 
have  good  eyesight.  It  has  been  the  experience  abroad  that  machine- 
gun  units  should  be  composed  of  men  with  a  mechanical  turn  of 
mind.  In  addition  to  the  above  qualifications  the  men  should,  of 
course,  be  intelligent  and  have  some  education,  otherwise  they  will 
not  understand  the  range  and  elevation  tables  and  the  theoretical 
side  of  the  machine-gun  fire  and  of  trajectories  of  bullets. 

Men  selected  for  machine-gun  service  are  chosen,  as  far  as  possible, 
from  men  who  have  had  from  six  months'  to  one  year's  service  in 
one  of  the  other  arms.  Others  selected  are  very  promising  men  from 
training  centers  who  have  completed  their  preliminary  training  and 
are  ready  to  take  up  their  machine-gun  work  at  once. 

Officers  and  men  found  unfit  for  machine-gun  service  are  relieved 
or  transferred  at  once.  Abroad,  every  member  of  the  detachment  is 
trained  in  such  a  manner  that  he  can  serve  on  any  duty  or  position 


24  MACHINE   GUNS  IN  TRENCH  WARFARE. 

at  the  gun.  ThJ8  training  is  necessary,  as  one  shell  may  disable  all 
the  numbers  operating  the  gun  and  the  remainder  of  the  detachment 
then  engaged  in  ammunition  supply  or  in  reserve  in  the  dugout  must 
take  over  its  service. 

After  all  are  trained,  the  most  efficient  are  appointed  gunners  and 
so  serve  until  disabled.  All  officers  and  noncommissioned  officers 
must  be  expert  in  the  operation  of  the  machine  gun  as  well  as  in  its 
theoretical  and  mechanical  employment. 

PHYSICAL  TRAINING.— All  members  of  the  detachment 
should  have  daily  physical  exercises,  running,  etc. 

Nothing  is  better  than  running  and  crawling  considerable  distances 
with  gun,  tripod,  and  ammunition  over  all  kinds  of  ground  and 
mounting  it  in  all  kinds  of  positions. 

KNOWLEDGE  OF  GUN.— While  the  officers  and  noncommis- 
sioned officers  of  machine-gun  units  must  be  experts  in  everything 
connected  with  the  nomenclature  of  the  machine  gun,  this  knowl- 
edge is  not  necessary  to  the  men  of  the  gun  detachment.  It  is  not 
necessary  that  they  should  know  the  names  of  all  of  the  parts  of  the 
gun,  but  it  is  necessary  that  each  member  of  the  gun  detachment 
should  have  just  as  intimate  knowledge  of  the  machine  gun  and  its 
parts  as  an  infantry  soldier  has  of  his  rifle.  They  should  be  required 
to  take  the  gun  apart  and  to  assemble  it  again  and  again  until  this 
becomes  second  nature,  and  they  should  be  quizzed  and  lectured 
about  springs  that  may  become  weak  and  causes  of  stoppages  and 
jama  until  the  ability  to  locate  these  also  become  second  nature. 
Not  until  such  intimate  knowledge  is  possessed  by  each  member  of 
the  detachment  can  a  gun  detachment  be  considered  ready  for  the 
advaced  work  of  machine-gun  employment.  \ 

FIRE   CONTROL.— Perfect  fire   control   will   require  careful 
training  of  all  grades  in: 
.     1.  Estimating  distances. 

2.  Pointing  out  and  picking  up  targets. 

3.  Fire  orders. 

4.  Transmission  or  passing  of  orders. 

5.  Visual  training. 

Visual  training  is  most  necessary.  It  develops  the  soldier's  powers 
of  observation  and  eye  for  the  ground,  quickens  his  intelligence,  and 
makes  the  designation  and  recognition  of  targets  very  easy. 

Training  in  transmission  of  orders  impresses  upon  the  soldier  that 
it  is  his  duty  to  make  certain  that  all  orders  passed  down  are  received 
and  understood  by  those  for  whom  they  are  intended. 

It  is  believed  that  the  finger  breadth  and  clock  systems  of  target 
designation  in  vogue  in  our  service  can  not  be  improved  upon  for 


MACHINE   GUNS  IN  TRENCH  WARFARE.  25 

training  in  target  designation  when  the  men  are  sufficiently  advanced 
to  receive  this  instruction. 

TRAINING. — Assuming  that  the  personnel  to  be  trained  is  so 
selected  that  it  is  ready  to  begin  machine-gun  work  at  once,  the 
training  of  machine-gun  units  may  be  divided  into  the  following 
parts: 

1.  Mechanical. 

2.  Formal  drill  (as  prescribed  by  the  Machine-Gun  Drill  Regula- 
tions) and  training  for  fire  control. 

3.  Advanced  drill. 

4.  Range  work.    But  not  a  shot  should  be  fired  on  the  range  until 
the  gunner  knows  everything  about  the  gun  and  its  use. 

5.  Construction  and  occupation  of  emplacements,  dug-outs,  com- 
munication trenches,  etc. 

6.  Tactical  training. 

7.  Training  with  other  troops. 

While  this  training  is  practically  that  given  for  open  warfare,  the 
present  war  has  proven  that  this  training  is  sound  and  adapts  itself 
easily  to  trench  warfare  whose  general  principles  are  exactly  the 
same. 

It  must  be  remembered  that  in  no  two  military  operations  will  the 
situation  be  exactly  the  same;  therefore,  machine-gun  units  must 
not  be  trained  for  any  particular  conditions  of  warfare.  General 
principles  and  broad  rules  alone  should  guide  their  training. 

The  fire  value  of  a  machine-gun  well  served  is  considered  to  equal 
that  of  at  least  50  riflemen  in  open  warfare,  and  it  is  claimed  by  some 
authorities  that  this  value  is  even  much  greater  in  trench  warfare. 

To  obtain  such  a  volume  of  fire  delivered  in  the  most  effective 
manner  would  seem  to  justify  an  enormous  amount  of  time,  trouble, 
and  expenditure  of  ammunition  in  machine-gun  training. 

MECHANICAL  TRAINING.— The  importance  of  this  training 
must  not  be  underestimated.  Its  thoroughness  will  depend  upon 
the  mechanical  knowledge  of  the  piece  possessed  by  the  officers  and 
noncommissioned  officers.  While  some  of  this  training  must  neces- 
sarily be  imparted  by  lecture  and  informal  talks,  in  the  main  it  is 
practical  and  must  be  acquired  by  the  individual  gunner  himself. 
The  machine  gun  and  all  accessories  are  given  to  each  man  in  turn 
and  he  is  required  to  take  them  apart  and  to  reassemble  them  until 
he  is  thoroughly  acquainted  with  the  place  and  the  use  of  each  part. 
The  names  of  parts  are  mentioned  from  time  to  time  until  the  gunner 
learns  the  nomenclature  of  the  piece. 

In  the  same  way  the  individual  members  of  the  detachment  are 
taught  to  mount  and  dismount  the  gun,  to  adjust  the  tripod,  and  to 


26  MACHINE  GUNS  IN  TRENCH  WARFARE. 

dismantle  it;  to  clean,  oil,  and  care  for  the  gun  and  all  of  the  parts; 
to  adjust,  read,  and  set  the  sights;  to  load  the  ammunition  strips  and 
belts;  load,  fire,  and  unload  the  gun,  with  dummy  cartridges;  to  feed 
the  gun,  to  locate  and  remedy  stoppages  and  jams,  and  to  pack  and 
unpack  gun,  tripod,  ammunition,  and  all  accessories  upon  the 
animals. 

Mechanical  training  must  be  reviewed  and  repeated  from  time  to 
time  so  that  the  gunners  will  not  become  ' '  rusty  "  in  their  knowledge. 

FORMAL  DRILL  AND  TRAINING  FOR  FIRE 
CONTROL. — Formal  drill,  including  the  allocation  of  duties  of 
all  members  of  the  unit,  is  prescribed  by  the  Machine-Gun  Drill 
Regulations. 

TRAINING  FOR  FIRE  CONTROL.— This  training  should 
begin  early  and  should  be  given  daily  until  all  members  of  the  unit 
are  proficient,  and  thereafter  the  subject  should  be  reviewed  fre- 
quently in  order  that  all  members  may  be  ready  for  actual  service 
at  any  time. 

RANGING. — The  instructor,  by  lecture  and  diagrams  on  black- 
board, explains  to  the  detachment  the  theory  of  the  trajectories  of 
bullets,  explaining  what  is  meant  by  the  cone  of  dispersion,  the 
danger  zone,  the  beaten  zone,  the  safety  zone,  the  danger  space,  the 
100  per  cent  zone,^the  effective  zone,  the  height  of  the  trajectory, 
the  line  of  sight,  angle  of  elevation,  etc. 

He  also  explains  why  it  is  necessary  to  find  the  correct  distance 
or  range  from  the  gun  to  the  target,  defines  ranging,  i.  e.,  "Any 
means  adopted  for  ascertaining  the  sighting  elevation  required  to 
hit  a  desired  object." 

He  explains  the  principal  methods  of  ranging: 

By  unit  of  measure. 
By  mil  system. 

;  In  depth .  -  { By    appearance    of 

1.  By  estimating  distances..^  h 

Method  of  averages. 
Lateral.     By  mil  system. 

2.  By  instruments.     (Special  course  of  instruction  must  be 
given  later.) 

3.  By  observation  of  bullets. 
Explains  other  methods  of  ranging: 

1.  By  use  of  maps. 

2.  Sound. 

3.  Information  from  other  troops. 

4.  Forward  and  back  reckoning. 


MACHINE  GUNS  IN  TRENCH  WARFARE.  27 

Explains  the  preparation  and  use  of  range  cards: 

For  attack. 

For  defense. 

Explains  value  and  method  of  observation  of  fire: 

By  signals. 

Methods  of  communication . .  •  _ 

Telephone. 

Messenger. 

By  quiz  it  is  ascertained  that  the  men  understand  what  has  been 
told  them.  The  members  of  the  unit  are  then  given  careful  prac- 
tical courses  of  instruction  in  all  branches  of  the  subject  in  the  open 
country.  Ranging  should  form  a  part  of  each  drill  thereafter. 

VISUAL  TRAINING.— As  stated  previously,  the  object  of 
this  training  is  to  develop  the  soldier's  power  of  observation  and  eye 
for  the  ground,  to  quicken  his  intelligence  and  make  the  pointing 
out  (Designation)  and  picking  up  (Recognition)  of  targets  easy.  This 
training  broadens  the  soldier's  military  vocabulary  and  enables  him 
to  describe  intelligently  what  he  sees,  as  well  as  to  recognize  quickly 
what  is  described  to  him. 

If  landscape  targets  are  available,  the  instruction  may  begin  at 
the  barracks,  preceded  by  a  lecture  or  an  informal  talk  by  the  in- 
structor. 

He  explains:  That  the  accuracy  of  modern  weapons  makes 
invisibility  a  necessity. 

That  invisibility  is  obtained  by — 

1.  Smokeless  powder. 

2.  Neutral  colored  uniforms  and  equipments. 

3.  Suitable  formations. 

4.  Movement  carried  out  under  cover  of  darkness. 

5.  Careful  study  and  use  of  the  shape  of  the  ground. 

That  a  trained  eyesight  is  necessary,  due  to  invisibility  of  the 
enemy. 

That  the  men  will  have  difficulty  at  first  in  observing  and  telling 
what  they  see,  due  to  differences  of  light,  to  the  different  appearance 
of  objects  in  town  and  in  the  country,  to  an  undeveloped  brain  power, 
and  to  a  lack  of  words  (military  vocabulary). 

He  impresses  upon  them  that  the  standard  each  must  aim  at  is — 

1.  Ability  to  distinguish  the  enemy  from  his  surroundings. 

2.  Ability  to  report  what  he  has  seen . 

3.  Ability  to  recognize  objects  described  to  him . 

4.  Ability  to  train  the  gun  on  the  desired  object. 

5.  Ability  to  study  the  ground  and  use  it  intelligently. 


28  MACHINE   GUNS  IN  TRENCH  WARFARE. 

After  these  preliminary  talks  the  instruction  is  given  in  the  country, 
where  a  varied  terrain  is  selected. 

1.  Single  silhouette  targets  and  groups  of  these  targets  are  placed 
in  different  positions,  with  various  backgrounds,  and  at  varying  dis- 
tances up  to  800  or  1,000  yards.    The  men  are  then  required  to  locate 
these  targets,  describe  their  location,  count  the  number  of  figures  in 
a  group,  discuss  characteristics  of  the  targets,  etc. 

2.  Individual  men  and  groups  of  men  then  take  the  place  of  the 
targets.    An  officer  is  sent  out  with  these  men  to  select  their  posi- 
tions, direct  their  movements  and  to  cause  blank  cartridges  to  be 
fired  so  as  to  train  the  unit  in  locating  sounds. 

The  units  under  instruction  then  locate,  recognize,  and  describe 
these  targets  in  the  same  way  as  was  done  with  the  silhouettes. 
They  also  state  the  direction  of  the  shots  fired,  their  number,  and 
whether  they  were  fired  by  riflemen  or  by  machine  guns. 

3.  Definite  lines  in  the  landscape,  areas  of  ground,  and  roads  are 
then  taken  up,  examined  and  described,  in  detail. 

Areas  of  ground  are  then  divided  into  sections,  both  laterally  and 
in  depth  (i.  e.,  foreground,  mid  area,  and  background),  and  these 
sections  are  examined  and  described  in  detail,  as  above. 

The  above  instruction  gradually  passes  into  the  Designation  and 
Recognition  of  targets. 

The  instructor  defines  Designation,  i.  e.i/'The  shortest  and  most 
easily  understood  description  of  an  aiming  point  by  a  commander." 

Also  Recognition,  i.  e.:  "The  gunner's  understanding  of  the  exact 
point  at  which  his  commander  wishes  him  to  aim." 

He  explains  that  accurate  ' '  Recognition ' '  is  necessary  to  insure 
that  the  cone  of  fire  will  strike  the  target  desired. 

In  this  instruction  the  enemy's  front  is  always  pointed  out,  and  the 
target  and  other  objects  pointed  out  must  be  described  as  seen  by 
the  naked  eye.  This  is  the  normal  method.  Aids  will  not  be  used 
except  when  necessary. 

Later,  when  the  instruction  has  advanced  sufficiently,  the  men 
are  taught  to  use  the  glasses  and  the  telescope;  they  are  also  taught 
the  "Designation"  and  "Recognition"  of  targets  by  the  aid  of — 

1.  Reference  points. 

2.  Finger  breadths. 

3.  Clock-face  method. 

All  of  this  instruction,  besides  increasing  the  military  vocabulary 
of  the  men  and  teaching  them  self-reliance,  gives  them  a  trained 
eyesight,  and  soon  they  will  be  able  to  recognize  quickly  the  points 
upon  which  to  aim  the  gun. 


MACHINE  GUNS  IN  TRENCH  WARFARE.  29 

As  soon  as  sufficient  progress  has  been  made,  the  machine  gun  is 
taken  into  the  open  country,  where  the  instructor  indicates  aiming 
points,  and  the  gun  is  pointed  at  the  target  as  the  gunner  under- 
stands it.  The  "Recognition"  by  the  gunner  is  always  checked. 

FIRE  ORDERS. — Whenever  fire  is  simulated,  correct  fire 
orders  should  always  be  given  for  the  class  of  fire  desired,  so  as  to 
accustom  the  men  as  soon  as  possible  to  receiving  and  executing 
these  orders. 

Before  giving  "Fire  orders,"  the  instructor  must  give  a  definition 
of  the  term,  and  he  must  also  define  "Ranging  fire,"  "Rapid  fire," 
"Searching  fire,"  "Traversing  fire,"  "Fire  with  combined  sights," 
"Overhead  fire,"  "Indirect  fire,"  etc. 

He  will  explain:  That  the  commander  will  take  a  position  from 
which  he  can  best  observe  the  fire  of  his  guns  and  the  movements  of 
his  own  troops  and  those  of  the  enemy. 

That  "Fire  orders"  may  be  verbal,  signaled,  or  written. 

That  they  will  be  by  word  of  mouth  when  practicable. 

That  they  may  be  transmitted  by  orderlies,  who  must  be  sure  to 
repeat  the  order  correctly  and  to  see  that  it  is  understood. 

That ' '  Fire  orders ' '  may  be  given  to  a  single  gun,  to  single  platoons, 
to  several  platoons,  or  to  the  whole  unit. 

That  necessity  may  require  them  to  be  given  direct  to  the  squad 
leader  instead  of  through  the  platoon  commander. 

That  there  may  be  occasions  when  orders  for  the  entire  unit  will 
have  to  be  sent  to  the  right  or  left  gun  and  then  passed  from  gun  to 
gun  along  the  line,  and  that  the  commander  would  then,  if  possible, 
take  a  position  on  or  near  a  flank. 

That  where  "Fire  orders"  are  given  by  word  of  mouth  or  repeated 
in  this  manner  they  must  be  given  calmly,  with  telegraphic  brevity, 
sufficiently  loud  for  everyone  concerned  to  hear,  and  with  pauses 
so  that  each  part  may  be  understood,  acted  upon,  and  repeated  if 
necessary. 

That  it  has  been  found  best  to  designate  the  range  first,0  to  indi- 
cate the  target  next,  and  then  the  number  of  rounds  and  class  of 
fire. 

That  fire  is  usually  begun  and  stopped  by  signals. 

That  alterations  of  the  range  are  given  by  the  words  "Up"  or 
"Down,"  adding  the  required  amount,  as  is  done  by  artillery  com- 
manders in  giving  their  fire  orders. 


<»  So  that  after  sights  are  once  set  it  will  not  be  necessary  for  the  gunner  to  take  his 
eyes  away  from  the  direction  of  the  target. 


30  MACHINE   GUNS  IN  TRENCH  WARFARE. 

ADVANCED  DRILL.— The  scope  of  the  instruction  given  in 
this  class  of  training  will  depend  upon  the  ingenuity  and  the  inter- 
est of  the  officers  conducting  the  training. 

This  instruction  should  be  given  where  there  is  a  varied  terrain, 
as  it  has  in  view  the  adaption  of  the  terrain  to  different  assumed  situa- 
tions and  includes  the  carrying  of  gun,  tripod,  and  ammunition  by 
crawling  and  creeping  over  all  kinds  of  ground  to  selected  gun  posi- 
tions without  being  seen,  the  occupation  of  these  positions,  the 
preparing  of  range  cards  to  all  likely  positions  of  the  enemy  and  to 
prominent  objects,  simulating  suitable  classes  of  fire  from  these 
positions,  the  selection  of  secondary  positions  and  preparing  range 
cards  for  them,  the  occupation  of  these  secondary  positions  without 
observation  by  the  enemy  and  simulating  fire  from  them,  then  with- 
drawing to  a  position  in  rear  or  on  a  flank  still  without  being  seen, 
practicing  fire  orders  in  all  of  these  positions,  and  communication 
to  the  rear  and  to  other  gun  detachments,  as  well  as  providing  for 
an  adequate  ammunition  supply  in  all  of  these  situations. 

This  instruction  naturally  merges  into  tactical  training,  as  the 
line  of  demarkation  is  rather  dim  when  instruction  is  begun  on  varied 
ground. 

RANGE  WORK.— This  ie  perhaps  the  most  important  part  of 
machine-gun  training.  After  the  men  have  passed  tests  in  their 
elementary  instruction,  their  range  training  is  begun.  A  varied 
terrain  must  be  selected  for  the  range  training  in  order  that  the 
proper  kind  of  instruction  may  be  given  in  all  classes  of  fire. 

The  training  consists  of  two  courses: 
I.  Instructional. 

II.  Advanced  (including  tests  for  classification  and 
combat  exercises). 

INSTRUCTIONAL. — In  this  course  officers  and  men  are  taught 
proper  firing  positions,  correct  laying,  steady  holding,  and  given 
practice  at  short  known  distances  in  fixed,  distributed  or  travers- 
ing, and  searching  fire. 

By  requiring  each  individual  to  prepare  the  machine  gun  for 
action,  to  mount  it  and  make  the  preliminary  tests  necessary  to 
assure  him  that  the  gun  is  "tuned  up, "  to  set  the  sights,  load,  and 
take  correct  firing  position,  to  hold  the  gun  steady  while  firing,  to 
correct  stoppages  and  jams,  and  then  to  unload,  dismount,  and  care 
for  the  gun,  all  in  turn  and  without  assistance,  will  develop  self- 
confidence,  a  most  necessary  quality  for  a  gunner. 

No  records  are  kept  of  this  firing  other  than  of  ammunition  ex- 
pended and  of  progress  made.  No  time  limit  should  be  imposed. 


MACHINE  GUNS  IN  TRENCH  WARFARE.  31 

Each  gunner  under  instruction  should  have  ample  time  to  learn 
his  lesson,  and  when  necessary  the  particular  firing  exercise  should 
be  repeated. 

The  instructor  watches  the  firer — not  the  target.  If  mistakes  are 
made  he  causes  the  fire  to  cease  and  makes  his  criticism. 

Range  discipline  is  carefully  maintained  and  all  safety  precau- 
tions are  taken. 

ADVANCED  RANGE  WORK.— The  aim  of  this  instruction 
is  to  train  the  units  in  all  classes  of  fire  and  to  such  a  degree  of  per- 
fection that  machine-gun  commanders  may  be  sure  that  the  fire  from 
their  guns  will  be  applied  to  the  best  tactical  advantage  when  the 
necessities  of  the  combat  remove  them  from  the  fire  direction  of 
superior  officers. 

The  practice  includes  ranging  fire,  observation  of  fire  and  making 
corrections  due  to  the  observation,  firing  from  successive  positions, 
firing  with  combined  sights,  night  firing,  searching  fire,  distributed 
or  traversing  fire,  fire  with  an  auxiliary  line  of  sight,  overhead  fire, 
fire  sweeping  reverse  slopes,  and  indirect  fire. 

The  ranges  being  unknown,  the  units  apply  their  previous  in- 
struction in  finding  the  correct  range,  or  fire  a  few  ranging  shots, 
observing  the  fire  and  making  corrections.  They  are  taught  to 
study  climatic  conditions  and  to  apply  corrections  of  elevation,  as 
well  as  the  use  of  wind  tables.  Here  they  have  practice  in  both 
classes  of  traversing  fire  on  screens  or  targets,  and  they  are  taught 
how  to  deliver  searching  fire  without  leaving  gaps  between  the 
effective  zones.  The  dangers  of  overhead  fire  are  pointed  out,  and 
the  units  are  taught  how  and  when  this  class  of  fire  may  be  used  with 
safety.  They  are  given  practice  in  sweeping  reverse  slopes  and  in 
the  use  of  indirect  fire,  as  well  as  practice  in  making  necessary  prep- 
arations for  and  executing  night  firing. 

After  this  course  is  completed  a  classification  test  is  given,  in 
which  a  time  limit  is  introduced  and  gunners  are  qualified  and  rated. 

After  the  tactical  training  is  well  advanced,  combat  exercises 
are  then  taken  up  in  connection  therewith,  the  targets  and  groups  of 
targets  being  arranged  to  appear  at  unknown  ranges  and  to  fit  in 
with  the  particular  tactical  situation  assumed. 

NOTES  ON  DIFFERENT  CLASSES  OF  FIRE.— An  a 
general  rule,  machine-gun  fire  will  not  produce  results  commen- 
surate with  the  amount  of  ammunition  expended  unless  the  target 
is  included  within  the  area  beaten  by  75  per  cent  of  the  bullets 
directed  upon  it. 

If  an  error  greater  than  half  tha  length  of  this  zone  is  made  in  esti- 
mating the  range,  the  fire  will  be  ineffective.  The  error  in  a  range 


32  MACHINE   GUNS  IN  TRENCH  WARFARE. 

obtained  by  a  range  finder  will  probably  be  3  to  5  per  cent  and  that 
by  other  methods  may  be  10  or  15  per  cent.  It  may  also  be  remarked 
that  the  probability  of  error  in  the  range  increases  with  distance. 
The  only  way  to  be-sure  that  you  have  the  correct  range  is  by  observa- 
tion of  fire,  which  is  not  always  possible.  If  observation  is  possible, 
the  observation  of  a  fe\v  ranging  shots  will  give  you  the  necessary 
correction,  but  ranging  shots  can  not  be  fired  when  surprise  is  in- 
tended and  is  of  importance. 

In  these  cases  an  effective  zone  is  made  certain  by  the  use  of 
"Combined  sights,"  or  by  "Searching  fire." 

These  classes  of  fire  are  used  against  deep  targets,  such  as  bridges 
and  roads. 

COMBINED  SIGHTS. — In  this  class  of  fire  two  or  more  machine 
guns  work  together  to  increase  the  depth  of  the  effective  zone,  by 
using  different  elevations  and  the  same  aiming  point.  The  effective 
zone  is  thus  lengthened  though  the  density  of  fire  is  reduced.  The 
difference  of  elevation  between  guns  will  depend  upon  the  number 
of  guns  available,  after  taking  into  consideration  the  probable  error 
in  obtaining  the  range,  and  the  effective  zone  for  each  gun  at  the 
particular  range  to  be  used.  The  differences  of  elevation  must  be 
such  that  no  gaps  will  be  left  between  the  75  per  cent  zones  of  the 
different  guns. 

It  seems  to  be  the  practice  to  use  combined  sights  differing  by 
an  elevation  of  100  yards  for  ranges  between  800  yards  and  1,200 
yards,  both  inclusive,  and  sights  differing  by  50  yards  above  1,200 
yards. 

The  machine-gun  commander  must  use  his  judgment  in  modifying 
the  application  of  the  above,  in  accordance  with  the  facilities  that 
he  has  for  accurately  obtaining  the  range,  so  that  the  desired  tactical 
advantage  will  be  gained  without  a  useless  expenditure  of  ammuni- 
tion. 

Firing  with  combined  sights  should  be  discontinued  as  soon  as 
accurate  observation  of  the  strike  of  the  bullets  can  be  obtained. 
A  simple  way  of  giving  the  fire  orders  for  combined  sights  is  to  give 
the  minimum  elevation  to  a  flank  gun  (usually  the  left)  and  to  an- 
nounce the  difference  of  elevation  desired.  If,  as  a  result  of  his 
observation,  or  for  other  reasons,  the  machine-gun  commander  wishes 
to  alter  the  sighting,  the  quickest  method  will  be  to  bring  the  ele- 
vation of  the  left-hand  gun  above  that  of  the  right-hand  gun  or  to 
lower  the  elevation  of  the  right-hand  gun  below  that  of  the  left- 
hand  gun,  according  to  whether  the  elevation  is  to  be  increased  or 
decreased. 


/  MACHINE   GUNS  IN  TRENCH  WARFARE.  33 

SEARCHING  FIRE.— This  class  of  fire  is  used  when  only 
one  or  two  machine  guns  are  available  and  combined  sights  will  not 
or  are  not  likely  to  overcome  errors  in  obtaining  the  correct  range. 
This  class  of  fire  requires  quite  a  degree  of  skill  on  the  part  of  the 
gunner  to  avoid  gaps  in  the  swept  zone. 

The  size  of  the  shot  groups  or  bursts  to  be  fired  will  depend  on 
the  nature  of  the  target  engaged. 

A  simple  method  of  using  this  class  of  fire  is  given  in  one  report 
a.s  follows: 

When  one  gun  is  being  employed  for  searching,  the  sights  arc 
adjusted  so  that  the  first  shot  group  will  include  the  lowest  range  to 
be  searched,  which  is  determined  by  the  expected  error  in  the  range. 

The  gun  is  now  laid  on  the  aiming  point  and  the  sights  adjusted, 
without  relaying  the  gun,  so  that  the  last  shot  group  will  include 
the  highest  range  to  be  searched.  The  line  of  sight  will  now  strike 
the  ground  short  of  the  aiming  point.  A  burst  is  now  fired  (10,  20, 
or  30  shots,  depending  upon  the  nature  of  the  target),  after  which 
the  elevating  wheel  is  turned  to  cause  the  next  burst  or  group  to 
strike  sufficiently  far  beyond  the  first  to  insure  an  overlap  of  the 
effective  zones.  This  is  continued  until  the  line  of  sight  is  again 
brought  on  to  the  aiming  point. 

When  using  two  guns,  the  left  gun  will  act  as  described  above, 
while  the  sights  of  the  right  gun  will  be  adjusted  in  the  first  instance 
to  the  highest  limit  to  be  searched  and  will  work  down  to  the  lowest 
limit. 

Searching  fire  will  be  discontinued  when  observation  of  results  is 
obtained. 

The  effect  of  ground  rising  with  respect  to  the  line  of  sight  must 
be  taken  into  consideration  when  either  combined  sights  or  search- 
ing fire  is  employed. 

DISTRIBUTED  OR  TRAVERSING  FIRE.— This  class  of 
fire  is  employed  against  a  linear  target. 

The  normal  method  of  traversing  is  by  means  of  a  series  of  small 
groups,  with  the  object  of  covering  as  wide  a  front  as  possible  and 
producing  the  desired  effect  without  too  great  an  expenditure  of 
ammunition.  In  the  normal  method  the  bursts  or  groups  consist 
of  only  5  or  10  shots. 

This  method  has  certain  disadvantages.  It  is  slow  and  requires 
careful  training.  The  effect  is  a  puncturing  one  at  regular  intervals 
instead  of  a  mowing  effect,  which  is  to  be  desired. 

The  other  method  of  traversing  is  called  the  "Swinging  traverse." 
In  this  method  the  traversing  clamp  is  kept  fairly  loose,  and  the 
°— 17 — 3 


34 

irun  is  8W#ng  evenly  fn»m  side  ;to  side. 


in  <:a.-e  of  u 

rush,  whjen  .11  10  normal  me!  hod  .\vmild  bo  Ux>.  ,s}owv    The  e.xpemli- 
iinv  of  ajjrun«i>^qni/is  #o.gr«a.t  when  the  '-^winging  tra\e. 
used  that  it  may  be  said  that:JJt4s)metbod.  wjji  Jbe  reserved  tos  emer- 
gencies.   tfire  qa^.be  dj^rihuU-d  by  this  method  over  30  >. 
front  at  close  ranges  in  five  seconds. 

NIGHT  FWNG.-Jf  cueuwafrnoi's  WJ1J  allow.it.  the  gun  in 
mounted  and  laid  by  day  and  left  till  night.     At  night  some  kin<l 

of  an,ai^xiliajfy  akniiig  uiaj-kia.p^Uwr^diiP^P^0^^16  ^un  :U1^  i"  '''"' 
\s-ilh  the  target  This  auxiliary  aiming-  mark  caai  l>«  a  -crceu  sc- 
oured to  the  open  fcide  of  a  box.  in  which  is  placed  an  oniiiuuy  jMge 
lantern  or  au  eJei.-iric  miv!.  Tlit.'  screen  is  marked  with  linjap  to 
permit  pf  ^e^fphing  ^nd  traversing  within  dcfmilo  limit.-,  li  the 
horizontal  ilines  of  the  3?neeij  fire  [J.,w^ch,^part.;  eadi  interval  will 
aubtend  a«ta^^^  IRiWnuteq^h^n  jt^BjCE^nis  10  yards  from  Uu- 
gun.  The  amount  th^t  W  E^i^wt^s^pr^a^nts  in^rangQ  |can:bereftfUly 
ascertained  t&ftJB  the  tafclp  ,al>Q»;ing  the  -angles  of  elevation  inr  lh«' 
gun.  The  .vertrtC-aUinefl  ai;e  ^^ncj^s  .Rpa^j  Flfuph/  will  give  a 
tiou  of  2  i^ti^^^Q.jjfarjdft^fr^ftgQi^^^t^screea  is  in  yards 
from  the  gun.  .tnioq  sniraif:  91(7 


gun;  .  pJeitioTR  ,js[  ,ei^FK>§€f4<  #P  that  the  £un  can  n<  »t  l><  • 
laid  during  the  day  or  where  fire  may  be  necessary  from  several 
-dUflwr«^t;pc^itionsi,aHiap^eTOep^i.YfJllji,aMe4a  be  -made  ta  bring  ih, 
gun  and  tripod  up  under  cover  of  darkness  and  mount  ijvso  as  t" 
open  fire  \sheiv  ipquired.  t  ,  .-,.  i 

Wlu'le  itds  still  light  itbe-igUfli-pfisiiJionriigBetepliQd,  This  of  pQurse 
must  be  selected  with  reference  to  the  target  it  w  intended  t<>  <-n- 
gage>  Astak^Jafli^pto<^jte!*«^<l!airi(JO(j^aLlisifH^ 
gun  position  and  roughly  in.  Unf);with;;<Hi©  lafget-atid  th^.gun  posi- 
tioii.  The.  officer  then  crawls  back  to:.tlje  gun  jxjsition  and  places 
aistaJfce  in  thsgrouad  in;a,oeuiiate  Higtim^nt  with  the  first  stake,  and 
the  target.  Over  tfeis  last  stajke  ;the  guU  -will  ,be  set  up  after  dark 
The  stakes  efeould  be  vertical  and  th.eio»e:atith6gwn  poaititai  shoul-! 
not  be  over  6  inches  above  the  ground  to  avoid-b«ingi  knocked  over 
when  the  tripod  is  placed  over  &;>;  lf<  mor^rihan,  one  target  id  to  be 
engngedvother  etaktw  are  aligned  ,l>?t^-e<»<,thie!tlCrgetd  au<i  the  stake 
marking  the  position  <oi  |theigun,f  iKangoa  and,  aijiglee  .Qf  ip-osition  -are 
then  takeii  to  the  different  .Htfgefcv 

"••-A  vl-uu  ?q93i  €t  qmsb  gnxaisvifii  -:>ih  borf; 

6  -  VI—  "66871' 


MACHINE  GUNS  Iff  TRENCH  WARFARE.  86 

If  owing  to  the  proximity  of  the  enemy,  it  should  be  found  im- 
possible to  place  a  stake  in  front  of  the  selected  gun  position,  then 
a  stake  is  first  driven  at  the  selected  gun  position  and  a  stake  in 
rear  is. placed  in^  accurate  alignmentr-w i£h 'it  -an,(Ji  the  target  to  be 
engaged. 

A  ft  or  dark  a  staice'tt)- yards  out  in  front  is  lined  np  with  the  other 
two  by  means  of  a  trench  lanter&s  Auxiliary  aiming  marks  are 
placed  at  night  at  the  exact  positions  of  the  10-yard  stakes.  The 
tripod  is  brought  forward  and  set  up  exactly  over  the  stake  at  the 
gun  position.  The  gun  is  then  mounted,  given  the  proper  eleva- 
tion," and  then  the  line  of  sight  is  brought  to  the  intersection  of  the 
central  horizontal  and  vertical  lines  of  the  night  firing  screen. 

Allowance  for  wiadage  is  now  made  by  using  the  vertical  lines  of 
the  screen. 

One  report  states  that  the  flash- of  the  machine  giAji  in  night  firing 
will  soon  disclose  its  'position,  unless  a  burlap -£iif tain^ia  used  to 
screen  the  flash. 


The  angle  of  departure.  .Ctak^R^Jfajp  -the  range  tables)  is  the  angle 
between  the  line  of  departure  of sthje1?  bullet  and  the  line  from  the 
gun  to  the  target. 

The  angle  of  position  is  the  angle  that  the  line  from  gun  to  target 
makes  with.  ..the  horizontal  line  through  the  gun. 

The  quadrant  elevation  is  the  angle  between  the  line  of  departure 
of  the  bullet  and  the  horizontal  line  tUjQUgh  the  gun.  It  is  the  sum 
of  angle  of  departure  and  the  angig^of  jKj&frJGjtt -jphen  the  target  is 
above  the  level  of  the  gun  and  to  fck<a  dj|lerence  of  these-angles  when 
the  target  is  below  the  level  of  the  gun. 

In  figure  1,  the  target  is  on  thu  same  level  as  the  gun,  and  .the 
angle  of  position  being  zero  the  quadrant  elevation  is  equal  to  the 
angle  of  departure.  The  aiming  point  is  the  target. 

In  figure  2,  the  target  is  above  the  level  of  the  gun,  and  the  quad- 
rant elevation  is  equal  to  the  sum  of  the  angle  of  departure  (taken 
from  the  range  table),ajid  the  angle  of  position.  The  aiming  point 
is  the  target. 

In  figure  3,  the  target  is  below  the  level  of  the  gun,  and  the  quad- 
rant elevation  is  equal  to  aivjrle  of  departure  diminished  by  the  an^le 
of  position.  Aiming  point  is  the  target. 

In  figure  -I,  the  liniui;  takes  place  at  night  and  as  the  target  can 
not  be  seen,  an  aiming  box  with  a  trench  lantern  inside  ia  placed  at 
A  as  an  aimin.Lr  point. 

a  The  proper  elevation  will  be  uhdef^ood  from  an  examination  of  the  figures 
shown  below. 


36 


MACHINE  GUNS  IN  TRENCH  WARFARE. 


Quadrant  Elevation 

Mg.  a. 

»  /.DOT  •»• 


of  Poaition  of  A 


5-  «, 


MACHINE   GUNS  IN  TRENCH  WARFARE.  37 

Before  dark  the  range  can  be  taken,  the  angle  of  departure  (taken 
from  the  range  table),  the  angle  of  position  and  the  quadrant  ele- 
vation for  the  target  can  be  determined.  After  dark,  as  soon  as 
the  gun  is  set  up  and  given  the  proper  elevation,  by  means  of  a 
clinometer  or  other  instrument  measuring  from  the  horizontal  plane, 
the  line  of  sight  is  brought  to  the  intersection  of  the  central  hori- 
zontal and  vertical  lines  of  the  aiming  box  by  means  of  the  tangent 
sight. 

To  hit  the  target  while  aiming  at  A,  it  is  evident  that  a  correction 
has  been  made  in  the  tangent  elevation,  which  in  this  case  (as  seen 
from  the  figure)  is  an  increase  equal  to  the  difference  of  the  angles 
of  position  of  the  target  and  that  of  the  aiming  box. 

NOTE. — The  formula  for  obtaining  the  angle  of  position  at  any 
range — 
Difference  in  height  of  gun  and 

target,  in  feet    X19.1=angle  of  position  in  degrees. 
Range  in  yards 

OVERHEAD  FIRE.— This  class  of  fire  refers  to  machine-gun 
fire  delivered,  from  the  rear  over  the  heads  of  our  own  troops,  either 
in  trenches,  or  advancing  to  the  attack.  It  may  be  employed  under 
certain  limited  conditions.  One  report  mentions  the  following 
factors,  all  of  which  tend  to  increase  the  difficulty  and  risk  in  em- 
ploying fire  of  this  nature  and  require  the  working  out  of  a  reason- 
able margin  of  safety: 

1.  The  state  of  the  machine-gun  barrel. 

2.  The  condition  of  the  tripod  and  the  nature  of  the  ground  on 
which  mounted. 

3.  The  degree  of  visibility  of  the  target. 

4.  Errors  due  to  obtaining  the  correct  range  and   to  climatic 
conditions. 

5.  Accuracy  of  laying  and  holding  by  the  firer. 

The  flat  trajectory  of  modern  ammunition  precludes  overhead 
fire  at  short  ranges,  for  the  gun  position,  our  troops,  and  those  of  the 
enemy  are  then  practically  in  the  same  place.  At  long  ranges  the 
dispersion  of  the  cone  of  fire  and  the  difficulty  of  getting  the  correct 
range  may  make  it  dangerous. 

This  authority  says  overhead  fire,  therefore,  may  normally  only 
be  employed  under  the  following  conditions: 

1.  When  the  machine  gun  is  fired  from  or  a.  a  commanding  posi- 
tion, or  across  a  valley. 

2.  When  the  distance  to  the  target  has  been  obtained  accurately, 
that  is,  by  an  expert  range  finder,  who  can  guarantee  the  distance 
as  correct  within  5  per  cent. 


»  MACHINE   GUNS  IN  TRENCH  WARFARE. 

:<.  When  the  fjurin.T  if  an  expert  firer. 

4.  \Vlim  fin  angle  of  MO  minutes  is-  formed  by  the  intersection  of 
imaginar^'line*  drawn  from  tiro  target  and  head*  of  friendly  troops 
lo  (begun,  the  distance  to  tho  target  being  L-000  yards  or  under.  If 
the  dibtkmte  to  the  target  IP  over  1,000  yards  and  not  more  than 
1.500  yard*,  the  angle  thus  formed  must  not  he  less  than  M  minutes. 
(These  angle*  may  be  different  with  our  ammunition  and  flatter 
trajectory.) 

If  the  distance  to  the  target  is  over  1,500 'yards,  direct  overhead 
fire  should  not  be  employed,  as  the  position  of  the  lowest  shot  of  the 
100  per  cent  c&ne  for  ranges  over  1,500  yards  is-  uncertain. 

It  is  remarked  b^'t!^&M6ferity  that- 1 lie  foregoing  may  be  modified 
prtividtd  tccdifot€  and  reliable  tibsertfition  is  obtained.  This-,  how- 
ever, is  a  matter  for  the  exercise  of  judgment  and  common  sense  on 
the  part  of  the  machine-gun  commander,  for- too  ttitich;  reliance  must 
not  be  placefLuppn; Usability  of  an  observer  t6"pick  up  the  cone  of 


1he  machine-gtm  cone  of  fire  ran  not  l>e  ])iek«l  up  correctly. 

There  are  several  methods  of  obtaining  the  safety  angletfof  30  and 
60  minutes,  in  use  abroad: 

(a)  By  m'eans  of  prismatic  field-glasses,  graticulated  for  the  par- 
ticular kind  of  ammunition  in  usel  For  example,  the  distance  be- 
tween the  zero  line  and  the  600  or  700  or  800  yard  graticule  would 
subtend  the  desired  angle  for  ranges-1,000  yards  or  under,  white  the 
distance  between  the  zero  line  and  trfe T,CfbO  or  1,100  yard  graticule 
would  give  the  angle  for  distances  between  l,000~and  1,500  yards. 
This  method  of  obtaining  tire  safety  angles  is1  unreliable,  since  it  is 
quite  possible  for  the  wrong  lines  to  be  used. 

(6)  By  means  of  a  machine  gunner's  protractor.  In  this  method 
the  protractor  is  held  vertically  at  the  full  length  of  the  cord'  from 
the  eye.  Lines  have  jfteVibusly  been  placed  upon  the  protractor 
at  such'  a  distance  from  cadi  other  as  to  marlc  angles  of  30  minutes 
and  eOTiiinutes  when  held  at  a  certain  fixed  distance  from'  the  eye. 

(r)  By  means  of  the  tangent  sight: 

Lay  the  gun  on  the  target  with  the  correct  elevation,  then  if  the 
distance  to  the  target  is  under  900  yards,  move  the  slide  up  400 
yards;  if  900  yards  or  mbre,  move  up  the  slide  256  yards.  In  each 
case  adopt  the  auxiliary  aiming  mark  thus  found .  Plate  15.  (These 
amounts  will  differ  with  our  ammunition.) 


MACHINE  ouire  r*r  TRENCH;  WARFARE.  39 

The  report  (Hflc'tis^-s'tte  advantages  and  disadvantages  of  this  lat- 
t.-r  method  as  folfow*. 

In  one  s-enso  if  is  against  the  pvinviph'S  of  machine-gun  training 
which 'emphasizes  the  impofctartte  of  'the1  gunner  looking 'at  the  target 
and  not  alang  his  sights'  when  firhig.  Again  the  pinner,  having 
carefully  maried'the-spot  on  which  the  sights  are  aligned,  is  trained 
to  take  the  heads  of  the  advancing infantry  as  his'aiming  mark  when 
they  reach  and  move  in  advance  of  this  spot,  or  rather  when  their 
heads  come  into  Ma  Ifcte  of  iftgiiti,'  a  TjIroteMiflg  which  may  not  always 
l>e  desirable. 

The  chief  advantages  are  that  eacH  gtasvean  o>rfairv  t'he  safety 
angle  for  the  particular  troops  he  is  supporting1;' when^t^  trWyps  \\  h" 
are  being  supported' pass  tfhe  s^>^1ttafrke'd/.a«!aA^iniing  mark,  the 
gniM^'eatt!stin-contihAi6>iil^^1)y'e;lleVating  tlie  gufi  PO  as  to  main- 
tain his  aim  on  their 'hea*. '  'AB  tttisf  ad\-atte^  c6tttfttitrts'/ Irfe  aim  is 
kept  on  their  heads  by  turning  the  elevati^fwTleje!:  By'this  means, 
ccK'ermgftre  is'itidititoined  ittWiltHi  Mendly  troops  reach-  tlfe-ehemy 's 
position.  The  conefr'of •ffi^'JCass  over  the  heads  of  iriendlj'-  troops 
with  a  margin  of  safety  at  each  advance,  and  seaa^frgrotiild'iii  rear 
of  the  defended  position  possibly  occupied  try  supports'atod1  reserves. 

The  disadX"Eflitagea!  ol  !«M*i4'fethod  can  1)6  miflimfeetl'  l>y  the 
macMne-givfllc(Wttma<adiei'iU8ittgii:  ]>rotractor  as  a  chwk  ow  tile  ifirer, 
and  this  id1  particularly  ne'efeis6ary'wheftfthe  nattri-4io*'th«f 'ground 
ontd  wiiieh'firfe  ib  being1  diredWd  gives  ar'folse  impression  a»  r'^arda  . 
the  limit  of  safety. 

INDIBfiCT  FIBE.— This  class  of  fire  wilt  be  need  mr fare 
occasions.  It  is  rendered  possible  by  the  "fixed  mountfeflgf"  of  the 
machine  gun.  Lewi&gunfi  and  others  of  a  similarii!atltfe"mu8f7iCT<?r 
be  used,  owing  to  the  fact  of  their  being  "air  cooled"  and  fired  from 
light,  mountings. 

I  ndirect  ftre  may  be  of  value  in  annoying  the  enenly  and1  affecting 
his  morale,  but  except  under  unusually  favorable  conditions,  can 
not  be  expected  to  inflict  serious  loss.  It  may  be  Used  to  rover 
areas  of  ground,  to  sweep -roads,  etc. 

It  requires  in  most  cases  a  great  deal  of  preparation  and  accuracy 
in  calculation.  Under  certain  conditions  it  mafy  positively1  be 
dangerous  to  our  own  troops.  Indirect  fire  facilitates1  fi*e  control, 
since  the  gunners  are1  not  exposed  to  aimed  rifle  fire.  In''this  con- 
nection, advantage'  of  cOi^eklntentiro^it^^B^my'tfartJltery  must 
not  be  overlooked. 

SPmiT-lJEVET,  METHOD.— \\  ith  (he  aid  of  an  ordinary  car- 
penter's spirit  level,  indirect  fire  can  be  quickly  and  accurately 


40  MACHINE  GUNS  IN  TKENCH  WARFARE. 

applied  with  machine  guns,  to  a  target  which  is  invisible  to  the 
firer.    The  conditions  necessary  for  success  with  this  method  are: 

(1)  The  target  must  be  visible  to  the  controlling  officer  from  a 
position  behind  and  slightly  above  the  gun. 

(2)  The  gun  must  be  far  enough  away  from  the  obstruction  to 
insure  the  bullets  clearing  it.    This  can  only  be  ascertained  definitely 
after  the  correct  elevation  has  been  placed  on  the  gun  to  hit  the 
target. 

(3)  The  gun  and  target  must  be  approximately  on  the  same  level. 

(4)  The  controlling  officer,  or  the  range  taker,  must  observe  the 
fire  through  field  glasses  or  the  range-finding  instrument  respectively, 
preferably  from  a  flank. 

The  method  of  employing  this  fire  is  described  as  follows: 

(a)  The  controlling  officer  raises  his  head  only  just  sufficiently  to 

enable  him  to  give  orders  to  the  gunner  as  to  aligning  his  gun  on 

the  target  for  direction  only. 

(6)  Having  finished  aligning  the  gun,  as  described  above,  the 

controlling  officer  now  gives  the  following  orders: 

1.  Sights  at  zero. 

2.  Level  gun  with  spirit  level. 

This  is  done  with  the  Viewers  or  Maxim  gun  by  laying  the  spirit 
level  on  the  top  of  the  breech  casings  and  then  by  moving  the  elevat- 
ing wheel  until  the  bubble  in  the  spirit  level  is  central. 

3.  Place  an  aiming  mark  where  sights  are  now  pointing  on  near 
side  of  obstruction. 

For  example,  a  stone  or  handkerchief,  or  anything  the  gunner 
can  see  plainly. 

4.  800  (or  whatever  the  range  to  the  target  happens  to  be  from  the 
gun  position). 

5.  Relay  on  aiming  mark. 

6.  Ascertain  if  shots  will  clear  obstruction  by  adjusting  the  sights 
for  the  distance  to  the  obstruction.    If  the  line  of  sight  now  clear?  the 
obstruction,  the  cone  will  also  clear. 

7.  Fire  (or  signal  of  fire). 

Since  the  gun  is  now  laid  with  the  correct  angle  of  elevation  for 
the  range  to  the  target  on  the  sights,  the  bullets  will  now  strike  the 
target  or  in  its  vicinity. 

Any  necessary  alterations  in  elevation  or  in  deflection  are  made 
according  to  the  results  of  the  fire  which  will  be  signaled  in  by  the 
range  finder  observing  through  his  powerful  instrument. 

This  method  must  not  be  employed  when  firing  over  the  heads  of 
our  own  troops. 


MACHINE  GUNS  IN  TRENCH  WARFARE.  41 

SPOUT  LEVEL,  CONTOURED  MAP,  AND  ELEVAT- 
ING DIAL. — From  the  map  ascertain  the  distance  to  and  difference 
in  height  between  the  gun  position  and  the  target.  From  this  work 
out  the  angle  of  position  in  minutes  by  the  formula. 

VIX19.1 

— gg—    =D, 

in  which  VI  is  the  difference  in  height  of  gun  position  and  target 
in  feet,  HD  is  the  distance  from  gun  to  target  in  yards,  and  D  is  the 
angle  of  position  in  degrees. 

Add  or  deduct  the  angle  of  position  thus  found  to  or  from  the 
angle  of  departure  for  the  distance  (from  range  tables),  according  to 
whether  the  target  is  above  or  below  the  gun  position.  This  will 
give  the  quadrant  elevation  to  be  placed  on  the  gun. 

To  place  the  required  quadrant  elevation  on  the  gun:  Level  the 
gun  by  spirit  level,  the  gunner  holding  the  while  slip  dial  around  till 
zero  is  under  the  pointer,  without  disturbing  the  bubble.  Clamp 
dial  to,  but  without  disturbing,  the  elevating  wheel.  Some  of  the 
guns  are  so  equipped  that  one  revolution  of  the  elevating  wheel 
equals  4  degrees  elevation  or  depression  on  the  gun.  To  obtain  an 
angle  of  elevation  of  8  degrees,  the  elevating  wheel  would  have  to  be 
revolved  twice.  To  set  off  a  lesser  amount,  use  is  made  of  the  sub- 
divisions of  5  minutes  into  which  the  4  degrees  are  divided.  These 
5-minute  subdivisions  are  easily  subdivided  by  the  eye. 

When  the  required  elevation  has  been  placed  on  the  gun,  put  a 
suitable  aiming  mark  in  position  between  the  gun  and  target;  the 
night  firing  screen  will  do  for  this  purpose.  Raise  the  slide  of  the 
tangent  sight  as  when  firing  by  night  without  altering  the  elevation 
of  the  gun.  The  direction  of  the  target  can  be  obtained  by  means  of 
the  traversing  dial,  or  prismatic  compass.  During  pauses  in  the 
firing  the  gun  must  be  relaid  on  the  auxiliary  aiming  mark.  The 
spirit  level  should  also  be  placed  on  the  gun  at  frequent  intervals 
and  the  gun  leveled.  If  the  zero  mark  on  the  dial  is  then  not  opposite 
to  the  pointer,  the  dial  should  be  undamped  and  adjusted  so  that 
the  zero  mark  is  in  correct  position,  as  described  above.  The  correct 
quadrant  elevation  should  then  be  placed  on  the  gun  and  the  tangent 
slide  altered  as  necessary. 

CLINOMETER  AND  CONTOURED  MAP  .-From  the  map 
ascertain  the  necessary  quadrant  elevation  to  be  placed  on  the  gun. 
Now  set  the  clinometer  to  the  required  reading,  and  place  it  on  the 
cover  with  the  arc  to  the  rear  and  with  the  long  edge  parallel  to  the 
axis  of  the  barrel.  Turn  the  elevating  wheel,  the  gunner  holding 
correctly,  till  the  bubble  is  central.  Place  an  auxiliary  aiming  mark 


42  MACHINE  GUNS  IS  TRENCH  WARBABE. 

in'  £63i8iflai   9!BfeAliip(aiA<jeBr  -houl d  be  placed  oh  thte-ftfin  M  frequent 
interval^  and;  the  elevation  checked.  JAId  O^l 

When  firimg-bver  theiheadfc  of  :our  awnjtnofrpsiJofclinojn^tef^Kluki 
be  used  unUxs  it^has  bewt&ted  and;  it nectevary.'*cortf)(>tv(\;  imme- 
diately prior  to  firing. 

GRATICTTLE  METHOD.— Byl  kheans  of  graticules  cut  across 
the  focal  planeiof  a  pair  of  prisoiatic  field- •gJassesi!  iaidlrtct1  fee  can 
bd iaa  qfuickly  applied  as /ordinary  direcfe'fire. 

These  graticules  represent  the  angles  of  devotion  for  ithegttn-  with 
sofae*  .pathticHlar  bind  o/artmunfeHW.  Thftitepmlost 'griaticnle  'rbjire- 
sertta i aetw;i an'd  life tlbsee  belo\r  represeskt'eVery  100  yards  upward 
from  2001  yards:  ; 

Proceed  as  follow?:  . ,  p  ed;  c. 

•  Jj.  l0btain;thBratJge'tath*ftargett:;!  ,i-  •.'.{•  b-r 

'2 .  Movw  to;  u  iprieitioii'Awlience  iyioti  can'obBerMe.  fene- target  tkrbugh 
gratitulatetttifield-glaseeai  look  at  the  target  in('»T!ioiri<i  wfeyithot'  tihe 
gzitusui®  r^presentiHg.  the  raiige-'tfat  tha>  tajg^t  i  faMs-  afciOBs  the  targets, 
then-Aodc  I or/» suitable  aiming  mark-  above;  th&targB*  !(«'h>k;hi-fflmTng 
marki  Bidtetr Ue  viaibleifrom  the-posit>ton.wheiSa;thte»gBnTJs"Hi)Dunted) 
and  >*ee/  whidh(  graitt«6le;fail8  across*  this-  aiiriingi'ini»rbJ 

(Ehe* frange^DorareBpond ing; to  this  gratictilei givefe  tlic'angfe  of  de- 
parture at -wihDcht;to  open-^ife;  neing;the  snitaible'  aiiiung  mark  to 
lay  the  gun  on.'  B^thlsimeandigaieat'accaraDy'ie  obtained  -white'  the 
gua«  and*  ifirer  are  invisible  to  tbe^^neiny.  ;  •  b 

.Uhis  >methbd  ibecomei;iiiaccnraie' wben'the  seVe  of  tb^of£ft^i<ndhg 
theigiatfksdated'glaBsfee  is  morethani^  feat'tftxiiJe-'thegan, 

I  tr  is  iioportanti  1x»;  get  i  an:  aiimirig ;  m  ark  •  virtnaaltyl  abavd  i  the  'target, 
maktB^ianyfiiTeceBsary  aWowafloe  ioY'Whid.  If  itib  fotikld  neeessttrV 
to  increase  or  decrease  the  elevation  afte?  fi?e  ihab  been  opehedy 
sirid^  the  posJtibni  of  /the1!  slide  does  nbt>  indicate  the1  range  tovthe 
taasget,  arioliberi  nwthod'  :othef  than  the  norinal'muftt  be 
( There  are  roughly  as  i  many,  clicks  on  th*:  ritch«(  ot'it 
sight  as  there  aire  ]kiia«dk«e<j8'oiiya»d8'iii  theirtulg^  »ti4llirangeq  bdb\r- 
1,500  yardel)  > 

IiONG  BA1T&E    SEARCHING    FI3l!Bi--In    ttenelb  "warfaiv, 
where  the  positions  of  our  own  and  the  enemy's  t«&6ps!af!e^ie9*Jy 
marked,  long>rdnge^6ilrtH£i^«r^d^r^thea>6^ 
may  eomtetimtefl'be  saiilyf  employed. 

Tb'  abtanr  the  best  resnlfa^  observation  vrf  thre1  strike  of  tlib  bnliets 
ia  eesetokifiit;  The  element  of  chance,  daw  to*  errors  ifi1  raaging,  cli- 
inatic  conditions,  etrora  as  to  the  exact  poaitJlon  of  the  guto;  etc., 
will  thus  be  removed. 


MACHINE   GUNS  IN  TRENCH  WARFARE.  4ft 

When  observation  of  results  is  possible,  fire  may  be  directed  on 
the  hostile  support  or  .reserve,  lines,  communication  tren< -lie.--,  ci<-. 
When  no  observation  is  posniblp,  the  moat  that  can  b<;  hoped  fur  is 
to  engage  an  area)  of  grotiad  with  the  object' of  sweeping  reverse^ 
slopes  of  hills  which  are  defiladed  from  fire  at>  sthbrfc  ranges,  inter- 
rupting trallic  on  roads,  etc. 

To  insure  the  safety  of  our  own  troops;! the- following  must  at  all 
t inios  l>o  strictly  adheiVxl  to: 

I.  No  target  should  be  engaged  at  a  r&nge  of  less -than  1,500-yards. 
L>.  Tim  guns  must  never 'be  more> Ihafar I/, 500 yards  -distant  from 

bodies  of  out-  own  troops,  over  \vhom  they  asre'firing, 

3.  \\lien1  the  guna  are  1,000  yasdB' or; under  "fromf  ourntrdops.  the 
range  at  which'  they' are  fired  must  be  such  aaJta-ididureitlie'ceriter  of 
the  cone  Wf  fii*e  psu&rig  at-  least  60  feet  oven  theai)  beads. 

When  the  guns  are  between  1,000  yards  andiJi,50^  yapd»iEroin  our 
o\vn  troops,  this  height  rmtst  bo  12&  f(3et. 

4.  The  p>isit  ton  of  OT*T  own ''troops: with-,  reference 'ticJ  the  gun  nmst 
be  accurate! y> ascertained. 

•  >.  Whon  there  is  ^negative  aoagle  of  pasitiorrf between i the  gttn. and 
target,  or  a  positive  angle  of  position  between  the.gU!n!and!ou!F  own 
troops,  the  heights  shown  iii  the  trajectory  tab-le -will  be  reduced. 
The  guns  musl.  therefore,  beiileved  back  t6  fire  at a-raflge<whichiwiil 
give  the  required' safety  limits' iiihder  these tfondifionfi. 

6.  Climatic  conditions  must  be  carefully  sthidied.  i 

7.  As  a -slight  sinking  of  the  tripod  d^in^/tho'ficingtiiflayae'rioualy 
al'fcct  the  safety  of  offf  own  troops,  owing  to1  the  aiitierdd'ahgle^of  dle- 
vation,  every  precaution  must  be  taken  to  prevent  this  happening. 
The  legs  of  the  tripod' should  be  firntlyimbeddediin'the'groUnd,  and 
provision  made  to  prevent  tlien\  ino vingft-om' their  original  rjoeition. 

8.  When  "traversing"  and  "searching"  is  used,  provision- must 

be  made  in  the  shape  of  wooden  battens,  etc..  to  limit  them  to  a  safe 

?,V\<}\?,    vAiV!^  sw\'\vw;>, 
amount. 

9.  A  worn  barrel  should  not  be  used. 

10.  All  calculations  must  be  carefully  checked  before  firing*. 

I 1.  Troops  over  whom  fire  ia  iff  be  opened  must  be  cautidned, 
and  a  certificate  to  this  effect  signed  by  the  machine-gun  cenimaider. 

12.  Clinometers-,  if  used,  must  be  tested,  and  if  necessary,  cor- 
rected, before  use.  To  direct  fire  on  a  targets  invisible  to  the  gtme, 
a  map  having  a  scale  of  not  loss  than  3  inchest  to  one  mile  must  be 

us.  M!.     In  order  to  find  the  correct  elevation,  the  map  must  be  con- 

_ 
toured,      tenrooa  ed  •y 


44  MACHINE  GUNS  IN  TRENCH  WARFARE. 

The  following  information  is  required  from  the  map: 

The  exact  position  of  the  gun,  the  direction  and  distance  between 
the  gun  and  the  target,  and  the  angle  of  positkih  of  target  with  re- 
spect to  the  gun.  Small  errors  in  the  position  of  the  gun  will  cause 
serious  errors  in  direction. 

The  position  of  the  gun  on  the  map  can  be  found  by  "resection.  " 
(Par.  34,  Engineer  Field  Manual.) 

The  direction  of  the  target  can  be  obtained  bv  means  of  a  compass 
bearing,  or  by  the  use  of  the  traversing  dial. 

To  find  the  direction  with  the  traversing  dial  proceed  as  follows: 

Select  some  convenient  object  visible  from  the  gun  position,  which 
can  be  identified  on  the  map  for  use  as  a  reference  object.  On  the 
map  draw  lines  from  the  gun  position  to  the  reference  object  and 
target.  Measure  with  a  protractor  the  angle  formed  by  these  two 
lines  at  the  gun  position. 

Place  the  gun  in  position  on  the  ground  and  lay  on  the  reference 
object.  Note  the  reading  shown  by  the  pointer  on  the  dial.  Add 
or  deduct  this  reading  from  the  angle  already  obtained  from  the 
map,  according  to  whether  the  reference  object  is  to  the  left  or 
right  of  the  target. 

When  the  reference  object  it  is  desired  to  use  can  not  be  identified 
on  the  map,  its  compass  bearing  must  be  taken  from  the  gun  posi- 
tion and  "plotted"  on  the  map.  The  required  angle  can  then  be 
measured  and  used  with  the  traversing  dial  as  before. 

To  place  the  required  elevation  on  the  gun  use  either  of  the 
methods  of  "Indirect  fire"  previously  described  (spirit  level  or 
clinometer). 

To  facilitate  the  making  of  notes  on  angles  of  elevation,  bearings, 
safety  of  our  own  troops,  etc.,  it  is  advisable  to  enlarge  the  area  to 
be  engaged. 

SiOPCS 


(<--  /tOO  yds. 

I 


By  selecting  the  most  suitable  range  it  is  easy  to  adjust  the  fire  of 
machine  guns,  so  that  reverse  slopes  of  hills  may  be  accurately  swept 
by  grazing  fire. 


MACHINE   GUNS  IN  TRENCH  WARFARE.  4.5 

The  following  example  will  show  how  the  suitable  range  is  selected : 

From  a  contoured  map  it  is  noted  that  the  enemy  occupies  a  crest 
line  180  feet  above  sea  level,  the  160-foot  contour  being  300  yards 
in  rear  of  the  crest  line. 

Our  troops  are  in  position  in  a  valley  which  is  120  feet  above  sea 
level. 

Deduct  120  feet  from  the  other  two  heights;  the  heights  above 
our  position  are  seen  to  be  60  and  40  feet,  respectively,  and  our 
bullets  are  required  to  descend  from  60  feet  to  40  feet  in  300  yards; 
that  is,  from  60  feet  to  54  feet  in  100  yards. 

Now,  inspect  the  trajectory  table  (Publication  No.  1923,  Descrip- 
tion and  Rules  for  the  Management  of  the  United  States  Rifle,  Caliber 
.30,  Model  of  1903).  Any  fall  of  6  feet  in  100  yards  will  not  do,  as 
it  is  necessary  to  arrange  that  the  bullet  shall  first  rise  to  60  feet. 
On  inspection  it  is  found  that  the  1,600-yards  trajectory  satisfies  the 
condition  as  to  rise  of  60  feet  and  that  there  is  approximately  the 
required  fall  (from  61.7  to  56.1  feet)  between  1,100  and  1,200  yards. 

If,  then,  a  line  is  drawn  on  the  map  1,100  yards  from  the  crest 
line  and  machine-gun  fire  is  directed  from  a  point  on  the  line  so 
arrived  at,  at  the  crest  line,  with  sights  at  1,100  yards  or  the  angle 
of  , departure  equivalent  to  this,  plus  the  angle  of  position  of  the 
crest,  the  bullets  will  sweep  the  reverse  slope. 

The  above  method  determines  the  best  position  for  covering  fire 
and  aids  in  selecting  positions  for  machine  guns  for  night  fire. 

RANGE  TABLES  AND  FIRING  DATA.— Plates  15  and  16 
show  two  kinds  of  range  and  firing  data  cards  in  use  by  one  of  our 
allies.  They  are  prepared  for  each  kind  of  ammunition  used.  A 
graticule  card  for  both  classes  of  ammunition  is  also  shown. 

AIDS  IN  THE  DETERMINATION  OF  RESULTS  OF 
FIRE. — Screens  of  suitable  size,  covered  with  paper,  are  used  at 
some  of  the  training  centers  for  determining  the  results  obtained 
from  different  classes  of  fire.  For  example,  if  it  is  intended  to 
sweep  the  reverse  slope  of  a  ridge  or  hill,  several  of  these  screens  are 
placed  along  the  slope  to  be  swept  and  between  bursts  results  are 
signaled,  or  after  the  exercise,  the  number  of  hits  are  counted. 

If  there  is  to  be  practice  in  overhead  fire,  rows  of  these  screens 
represent  our  troops  at  different  stages  of  their  advance  and  the  safety 
angles  for  this  class  of  fire  are  determined  by  sighting  at  the  tops  ol 
the  screens.  There  must  be  no  hits  on  these  screens.  Other  screens 
represent  the  enemy. 

In  the  same  way  screens  represent  troops  on  a  bridge,  along  a  road, 
Dr  the  positions  of  supports  and  reserves,  when  practice  is  had,  in 


4»  MACHINE  &TTNS  IN  TRENCH  WARFARE. 

"searehHig/1  otifefingiwith  combined  sights  and  -also  during  night 
firing. 

CONSTRUCTION  OF  EMPLACEMENTS,  DUGOUTS. 
COMMUNICATION  TRENCHES,  ETC.—  At  all  tniininy  .•.•ni<-r- 
aBectionof  a  >  '<def  ended  'amV  or  a  system  of  fjold  workp,  has  been 
laid  out  and  constructed  according  to  the  conditions  imposed  by  the. 
terrain,  with  firing  Srenohes/  support  trendhes,  all  kinds  of  emplace- 
ments 'foe  giiaehiiaei  gimg,  dugouts,  eofcuarinidatioir  trenched,  reserve 
<lucroiitsv»r*tottn£tk«i(<!!h*mbeW3,ie!itangleHi;cnte<  lookoxit  'poets.  lines 
of  communications,  etc.,  ju«*;sts'  *hey-  exist  at  tfae-  front/  '  These  are 
kept  in  re,  pair  and"  gvadUailiyeiitended  by  the  labor  of  the  men  under 
training.  :>  At  <th'eiprbpe*!tii»e^  during  the  training  peried>  hiaohine- 
.min  uiri^d«cttpyi&ese  enticements  and  are  taught  the  routine-  of 
i  ho  t  renches,'  vlitriag  *  B44rt)«r  periods*.  They  c<»id<ictl>'ntght  lirinir 
f¥^rtf'tft^s«««¥plac^mentsand  are  tau-^ht  tlicir  duties  ]>otlv  in  attack 
arid  defettee  iifldea1  cotiditiohA  as:  realistic  y'thtey  ^n  'be-«iide. 

TAOTTOAIi  TRAINING. 

tfe'<l)^Bed^nnaife»ali^e  land  study  of  ground.—  A  rcoorinaiisarice 
May  %te  toddfe'iri-t^oi  ^ayfej'l.  «.,  by  'actually^  going  'd^p-the  ground 
attd1  fey  «tuitfyikg4t  \*ith(  glasses, 

The  latter-will  'b^She  moet  usual  metHodV^theJtraiHing'initHc 
study  of  the  ground,  eeleeiioii  of  gun  pofltioiisJ'cdrtceAted  lines  of 
adV^S'smd  *te*r«i«-yl^WI,%ttJbt!Ae  continual-arid  thoft>«fc:;-: 

All  gttide'8isiHi«14ffi^*fe'^»d  'fett 
Aoiifif  c^nstant'fy  p^aet 

selecting  'gvttf'  p^iflons.  liii.-s  of  axlvance,  et<».,  in  advance  of  that 
pomtr'-'Tlfey'SWeff'g*  *tfr^a^  ttfrftW  if  their  Belec^tidn  has  *^ 
correct  -n7/'0lla  (>8^;  ^  noijinirmmf;  io  .'tod  TH  rn 


directed  to  occupy  the  •  positions  chosen1.'  !  -The  officers  ! 
moVements,  correct  eifors,  or  suggest  better  methitfeW  eaying^mt 
the  movements. 

(2)  Selection  of  gun  position^.—  Daily  in?trm-ii<.n  should  be 
given  in  the  selection  of  gun  positions.  Ati  dffieei-^ecoftipttnied  by 
a  range-finder  servant  makes  The  selection.  The  actual1  position  of 
the  gun  must  te  chosen  from  a  lying  position,  ihe  person  -selecting 
the  position  raising  himself  on  hi?  elbows  until  his  eyes  are  on  the 
level  of  the  gunner  \vheu  firing  the  gun. 

The  officer  also  selects  the  position  from  which  he  will  command 
the  guns.  The  range-finder  sergeant,  as  soon  as  a  position  has  been 
setefte^d',  make's  'a'  range  card  for  the  position,  entering  thereon  the 
ranges  to  all  prominent  objects.  The  range-finder  sergeant  muef  hot 


MACHINE   G-TTNS  IN   TRENCH  WARFARE.  47 

accompany  the  Officer  so  closely  as  to  make  a  roiiHpifuoim  target  for 
the  enemy. 

The  office  then 'selects  an  alternative  position  for  each  gnn,  which 
must  be  capable  of  being  reached  under  cover  from  the  first  gnn 
position,  and  the  range-tinder  sergeant  then  i prepares  a  range  card 
for  that  petition. 

(3)  Method  of  oring-ing:  up  the  guns.-'*Ba'fihg  ulcered  a  gun 
position,  the  officer  signals  i.,  i!-.--  sergeant  whose  squad  is  to  occnr.i- 
it  to  join  him.     The  position  oi  the  .-un   the  <••••;:  ;.-.  me  range  card, 
and  the  route  of  "the'gtm'toJte  posi-ti ..u -an*  then  .-riven  \<-,  sergeant, 
and  he  condiictefci^squa^cr.siirnali'  it  to  its' position 

The  ;*-:.;::  li^proactoes-^Adef 'cover  to  a  point  us  near  the  position 
as  possible  before  unpacking  gun,  tripod,  and  ammunition.  'From 
this pwition  theseare  carried  forward  by  hand. 

The  member  carrying  the  tripod  leads  and  sets  it  up  under  the 
direction  of  the  sergeant.  The  member  with  the  •gun  comes  next. 

Then  come  the  ammunition,  spare  part?,  extra  barrel,  en •.  Th; 
packs  are  moved  >to  a  tmitable  covered  position,  if  possible,  out  :' 
the  direct  line  of  fire.  !It -should  not  be  necessarv  (  <j:-  ;:•  an \  orders 
to  the  noncommissioned  Officer  in  char1-  m  the  -parks.  He  should 
be  trained  to  >ke4p;theT&  ufidet cover  and  to  maintain  communu-a- 
tion  between  them  and  the  guns,  sending  notice  of  any'  chancre  in 
his  position. 

(4)  Arrangements  for  ammunition  supply.-  Ore:'!  anention 
must  be  given  to  the  maintenance  of  an  adequate  ammunition  sup- 
ply.   Too  much  ammunition  must  not  be  carried  to  the  gun  posi- 
tion, for  in  case  of  a  retirement  or  a  sudden  chancre  of  position  it,  may 
be  lost.     Ammunition  carriers-bring  up  limited  amounts,  being  eare- 
ful  not  to  expose  themselves  and  thus  give  away  the  position  of  the 
gun.     If  the  distance  to  the  packs  is  great,  a  relay  will  be  formed, 
the  carrier  from  the  pack  meeting  the  carrier  from  the  gnn  at  a 
halfway  point. 

(5)  Methods  of  communication. — In  training,  all  methods  of 
communication  should  be  used  and  prsictieed;  i.  o.,  orderlies,  sema- 
phore, other  methods  of  visual  signaling,  and  telephon* 

Fire  orders  and  target  designations  should  be  given  habitually  on 
the  ground  by  these  methods,  and  always  in  the  lying  position,  so 
as  to  practice  communication,  as  well  as  the  habit  of  concealment 
so  necessary  when  in  the  presence  of  the  enemy. 

(<j;  Reference  points.— These  should  be  selected  by  the 
niachine-g\in  commander  and  communicated  as  soon  as  possible  to 

the  sqiiaid  leaders',  so  as  to  make  the  pointing  out  of  targets  < 

. 


48  MACHINE  GUNS  IN  TRENCH  WARFARE. 

(7)  Likely  targets.— Squad  leaders  and  members  of  the  squad 
should  be  practiced  frequently  in  selecting  places  that  are  likely  to 
be  occupied  by  the  enemy.    Officers  should  also  select  these  posi- 
tions and  point  them  out  to  the  men.    This  practice  will  train  the 
men  in  finding  such  positions  and  will  make  the  pointing  out  and 
recognition  of  targets  easier. 

(8)  Changes  of  position. — Practice  should  be  given  in  with- 
drawing the  gun  quickly  from  one  position  and  occupying  an  alterna- 
tive position  without  being  observed  from  the  direction  of  the  enemy. 

(9)  Enemy's  machine  guns. — One  or  two  guns  should  be  sent 
to  take  up  positions  that  would  likely  be  occupied  by  the  enemy 
and  then  the  squads  should  be  practiced  in  locating  them  by  sound 
and  with  telescopes. 

(10)  Team  work. — This  practice  is  most  valuable.     It  consists 
in  teaching  cooperation  by  the  different  squads  in  concentrating  the 
fire  of  all  guns  upon  a  particular  target,  changing  the  fire  to  another 
target,  distributing  thd  fire  among  several  targets,  crossing  fire  with 
that  of  neighboring  guns,  using  traversing  fire  by  some  guns,  and 
overhead  fire  by  others  and  other  combinations. 

(11)  Choice  of  gun  positions. — Questions  of  concealment  and 
the  kind  of  fire  desired  will  have  great  weight  in  the  choice  of  a  gun 
position;  i.  e.,  whether  we  desire — 

Enfilade  fire. 

Overhead  fire. 

Long-range  fire. 

Fire  against  houses,  etc. 

Fire  against  enemy's  machine  guns. 

Concealment  from  enemy's  artillery. 

Other  considerations  may  control  the  choice,  as — 

Lines  of  advance  and  retreat. 

€over  for  ammunition  carriers. 

Facilities  for  control  of  guns. 

Alternative  positions. 

Positions  to  be  avoided  have  been  mentioned  before,  such  as 
obvious  positions,  or  those  easy  for  the  enemy  to  pick  out,  and  those 
easy  to  observe,  as  well  as  those  near  prominent  objects,  etc. 

TRAINING  OF  MACHINE-GTJN  UNITS  IN  COMBINA- 
TION WITH  OTHER  TROOPS. — No  training  can  be  considered 
complete  unless  the  machine-gun  units  have  been  trained  in  combi- 
nation with  other  troops. 

In  this  course  of  training,  the  different  units  should,  in  turn,  be 
given  all  of  the  different  rdles  that  machine-gun  units  will  have  to 
play  on  the  field  of  battle  in  open  warfare,  and  in  both  classes  of 


MACHINE  GUNS  IN  TRENCH  WARFARE.  49 

trench  warfare.  Careful  and  repeated  instruction  is  given  in  the 
different  duties  necessary  in  an  attack  of  the  enemy's  trenches  in 
trench  warfare;  i.  e.,  that  of  accompanying  the  infantry  line,  of 
protecting  the  flanks  of  our  line,  in  the  delivering  of  overhead, 
supporting  fire,  or  of  indirect,  searching  fire  against  the  supports 
and  reserves  of  the  enemy,  etc. 

None  of  this  training  should  be  given  until  the  machine-gun 
units  are  more  or  less  expert  in  all  of  the  different  kinds  of  training 
outlined  above,  especially  that  classed  as  range  work.  In  this  train- 
ing, the  theoretical  principles  of  the  previous  instruction  are  actually 
applied  with  troops  and  the  lessons  taught  are  brought  out,  as  well 
as  the  importance  of  cooperation  not  only  between  the  guns  and 
the  troops  they  are  assisting  but  also  the  necessity  for  close  cooper- 
ation between  the  guns  themselves. 


SYNOPSIS  OF  PRINCIPLES  APPLICABLE  TO  MACHINE 
GUNS  IN  TRENCH  WARFARE. 


COOPERATION. 

Between  machine  guns  of  any  particular  section  of  a  defensive 
line. 

Between  machine  guns  of  adjacent  sections  and  brigades. 

All  ground  in  front  swept  by  cross  fire,  forming  belt  of  fire. 

Machine-gun  commanders  and  section  commanders  must  be 
conversant  with  the  situation. 

Cooperation  of  machine  guns  from  a  flank  against  points  where  the 
enemy  is  very  close  must  be  arranged  for. 

TAKING  OVER  TRENCHES. 

Before  taking  over  trenches,  the  machine-gun  commander 
should,  if  possible,  reconnoiter  the  whole  line  and  note — 

Position  of  each  machine  gun  and  area  covered  by  it. 

Number,  position,  and  nature  of  any  extra  emplacements,  dug- 
outs, splinter  lookout  posts,  or  other  work  to  be  done. 

Positions  and  methods  of  communication  between  himself  and 
his  officers  commanding  sections,  and  between  them  and  their 
guns. 

He  then  issues  any  necessary  machine-gun  orders. 

BO1CBARDMENTS. 

With  a  view  to  reducing  losses  during  bombardments  observe 
these  rules: 

During  bombardment  by  the  enemy,  dismount  machine  guns  and 
place  them  in  strong  dugouts,  or  if  none,  in  bottom  of  trench. 

Tripods  are  left  in  position,  so  guns  can  be  mounted  quickly. 

Machine  guns  when  dismounted  will  be  wrapped  in  strong  water- 
proof covers  to  prevent  clogging  with  dirt  from  shell  fire. 

Gunners  not  retire  to  one  dugout  or  to  one  part  of  trench,  so  all 
will  be  struck  by  one  shell. 

After  bombardment,  two  men  mount  gun — others  remain  under 
cover. 

When  enemy  attack  is  launched  without  covering  machine  gun 
and  infantry  rifle  fire  from  the  flanks,  and  when  speed  is  especially 
important,  undue  attention  is  not  paid  to  exposure. 
50 


MACHINE   GUNS  IN  TRENCH  WARFARE.  51 

Strong  dugouta  are  provided  near  each  niachine-gun  emplace- 
ment for  the  men. 

Strong  splinter-proof  lookout  posts  are  provided  for  use  during 
a  bombardment  while  the  machine  guns  are  in  the  dugouts. 

Three  or  four  men  are  sufficient  in  front  trenches — remainder 
are  kept  in  reserve  trenches. 

During  a  bombardment  by  our  artillery,  machine  guns  should 
not  be  fired  except  at  a  very  favorable  target. 

AMMUNITION. 

Ammunition  supply  must  be  carefully  thought  out. 

British  have  8  full  belts  and  4,000  rounds  in  unopened  boxes  with 
each  gun. 

Other  full  belts,  belt-filling  machines,  and  4,000  in  unopened 
boxes  with  spare  gunners  at  central  depot  in  reserve  trench,  or  other 
suitable  place. 

Arrangements  for  filling  belts  or  strips  in  dugouts  or  reserve 
trenches. 

In  wet  trenches  care  taken  to  keep  belt  boxes  out  of  the  mud. 

Belts  and  boxes  kept  in  ammunition  recesses — clean  and  dry. 

Ammunition  not  kept  all  together  in  one  place. 

Ammunition  kept  dry  as  possible  and  inspected  daily.  Each 
round  turned  to  prevent  sticking  in  belts. 

EMPLACEMENTS. 

One  emplacement  reserved  for  each  machine  gun  as  battle  emplace- 
ment— never  used  except  to  meet  enemy  attack. 

Several  alternative  emplacements  are  made— one  should  be  open 
for  firing  over  the  parapet. 

Every  emplacement  is  numbered  and  marked  and  has  a  range  card 

in  it. 

Emplacements  numbered  from  right  to  left  in  each  brigade. 

After  firing  from  one  emplacement  move  gun  quickly  to  another — 
prevents  location  by  artillery  and  is  good  practice. 

Firing  from  dummy  emplacements  will  deceive  enemy  as  to  posi- 
tion of  emplacements  and  to  the  number  of  guns. 

Emplacements  and  dugouts  are  always  kept  in  good  repair. 

In  each  emplacement  limits  to  which  machine  gun  may  be  trav- 
ersed with  safety  to  friendly  troops  are  marked  with  posts  or  sand- 
bags. 

When  the  machine-gun  position  is  liable  to  be  rushed  due  to  weak 
wire  entanglements,  or  if  due  to  the  closeness  of  the  enemy  trenches 
it  is  subject  to  attack  by  bombers,  the  guns  are  dismounted  and  kept 
in  the  'dugouts  during  the  daytime. 

Smoke  helmets  are  worn  when  firing  is  kept  up  in  bombproofs. 


52  MACHINE   GUNS  IN  TRENCH!  WARFARE. 

OVERHEAD  FIRE. 

Our  troops  should  be  notified  before  firing  over  them. 

LAYING  OUT  TRENCHES. 

When  trenches  are  dug  deliberately,  machine-gun  positions  are 
chosen  first— this  enables  trenches  to  be  held  with  minimum  number 
of  riflemen. 

RELIEFS. 

Detachments  relieved  systematically  to  give  officers  and  men 
sufficient  rest. 

Three  or  four  men  in  front  trenches  at  one  time  and  remainder  in 
reserve  at  central  dugout,  or  ammunition  depot,  will  enable  front- 
line men  to  be  relieved  every  24  hours. 

Units  should  be  relieved  every  few  days. 

Other  troops  assist  machine-gun  organizations  in  carrying  ammuni- 
tion, revetting  material,  etc.,  when  necessary. 

CONTROL  OF  GUNS. 

The  machine-gun  officer. 

Establishes  himself  at  place  where  messages  can  always  reach  him. 

Keeps  in  touch  with  his  guns  and  with  the  officers  of  the  line  of 
trenches  he  is  assisting  to  defend. 

Arranges  for  fire  control  and  direction — usually  in  the  trenches  a 
man  is  placed  in  charge  of  each  gun  with  definite  instructions  what 
to  do  in  various  eventualities. 

ENEMY  MACHINE  GUNS. 

Telescopes  are  of  great  value  in  spotting  enemy  machine  guns, 
observation  of  fire,  etc.  Training  of  both  officers  and  noncommis- 
sioned officers  required  to  get  best  results  from  telescopes. 

If  enemy  machine  guns  located  and  doing  no  material  damage, 
leave  them  alone.  If  fired  on  they  will  change  position.  If  we 
know  their  location,  when  our  attack  is  launched,  our  machine  gun' 
can  keep  down  their  fire. 

CLEANING. 

J^fachine  guns  and  all  stores  cleaned  at  least  once  daily. 

BRIGHT  PARTS  OF  MACHINE  GUNS. 

Painted  khaki  color  to  prevent  reflection. 

PERISCOPES. 

Every  one  trained  in  their  use.  Never  used  near  gun  position  but 
to  the  side. 

POSITIONS— KNOWN  TO  ALL. 

Position  of  machine-gun  commander  of  any  section  must  be  known 
to  everybody.  Every  gunner  must  know  the  position  of  every  gun 
whether  it  be  in  the  front  line,  in  the  support  trenches,  in  reserve, 
or  in  position  in  rear;  also  the  best  way  to  them.  , 


MACHINE  GUNS  IN  TRENCH  WARFARE.  53 

TRAVERSING. 

The  "Tap"  traverse  is  the  normal  method.  For  sweeping  para- 
pets and  repelling  rushes  the  "Swing"  traverse  is  used. 

FIRING  WITHOUT  TRIPODS. 

Gunners  should  have  practice  in  this.  When  emplacements  are 
destroyed  or  tripods  disabled,  machine  guns  must  he  fired  over  the 
parapets,  with  only  parapet  rest. 

SHOVELS. 

In  the  attack  a  small  shovel  is  strapped  to  the  back  of  one  gunner. 

OPENING  FIRE. 

It  is  a  point  of  honor  for  a  machine  gunner  to  always  have  his 
machine  gun  "tuned  up  "  and  ready  for  any  emergency. 

VERY  PISTOLS. 

Every  machine  gun  has  a  Very  pistol  to  show  up  enemy  night 
attacks  and  to  enable  fire  to  be  directed  upon  them. 

BOMBERS. 

Two  or  three  bombers  protect  the  machine  gun  during  an  attack; 
also  when  the  opposing  trenches  are  close  together.  This  enables 
machine  guns  to  be  used  to  best  advantage.  All  gunners  receive 
instruction  in  bombing. 

ORDER  BOARD. 

One  in  each  emplacement. 

(Sample.)  Order  for  sentinel  and  gun  commander  at  No.  6 
gun  position. 

Fire  only  to  be  opened  by  order  of  gun  commander  unless  emer- 
gency arises,  in  which  case  sentinel  uses  his  own  initiative. 

When  relieving  another  gun  team  or  sentinel  ascertain: 

Whether  gun  has  been  fired  during  the  relief. 

If  fired,  what  the  target  was. 

If  fired,  from  which  emplacement. 

The  sentinel  will  inspect  the  gun  before  taking  post. 

The  sentinel  will  have  accurate  information  of  points  on  range 
card. 

In  case  of  alarm  or  gas  attack  sentinel  will  wake  gun  team. 

The  gun  will  not  bo  mounted,  except  during  darkness,  unless  the 
situation  makes  it  necessary. 

The  gun  will  be  cleaned  daily,  and  weight  of  fusee  spring  noted 
both  morning  and  night. 

Ammunition,  spare  parts,  and  hyposulphite  solution  will  be  in- 
spected daily. 

The  lock  spring  (return  or  hammer)  will  never  be  left  compressed. 


64  MACHINE  GUNS  IN  TRENCH  WARFARE. 

It  is  sufficient  to  half  load  and  press  the  double  button  with  the 
Vickers,  or  to  place  a  magazine  in  position  on  the  magazine  post  of 
the  Lewis  when  mounting  the  gun  at  night. 

In  order  to  meet  an  attack  complete  the  loading. 
All  dugouts,  emplacements,  ammunition  chambers,  etc.,  belonging 
to  the  gun  position  will  be  kept  clean  and  in  repair. 

Here  follows  any  special  orders  of  the  position. 

MACHINE  GUNS  IN  ENEMY  GAS  ATTACK. 

Gas  affects  working  parts  of  a  machine  gun;  also  the  cartridges  in 
the  belt.  If  long  exposed,  impossible  to  fire  the  gun. 

Gas  is  heavier  than  air — sinks  to  bottom  of  trench  or  dugout.  Guns 
in  dugouts  or  low  emplacements  must  be  removed  at  once  and  placed 
to  fire  over  the  parapet. 

A  sprayer  is  kept  with  each  machine  gun. 

There  are  two  courses  open  to  the  machine-gun  officer: 

1.  To  order  fire  to  be  opened  with  a  view  to — 

Preventing  the  enemy  leaving  his  trenches  and  keeping  down 
their  fire  so  as  to  enable  his  own  troops  to  keep  their  heads  high. 

Encouraging  his  own  troops. 

Keeping  his  machine  guns  working,  as,  while  in  movement,  the 
various  parts  are  less  affected  by  the  gas  and  the  firing  of  the  machine 
gun  has  the  effect  of  dispersing  the  surrounding  gas  to  a  certain  extent. 

2.  To  reserve  his  fire,  with  a  view  to  taking  advantage  of  a  careless 
advance  on  the  part  of  the  enemy  following  up  their  gas.     In  this 
event  he  should  use  his  sprayer  constantly. 

The  course  of  action  adopted  will  depend  on  the  effect  produced 
by  the  gas  on  the  troops  in  his  trench. 

.  COMMUNICATION. 

Is  difficult  in  defense,  owing  to  the  cutting  of  telephone  wires. 

Is  more  difficult  in  attack,  as  enemy  sometimes  places  a  barrage  of 
fire  behind  our  troops  after  they  have  gone  forward. 

For  these  reasons  every  form  of  communication  must  be  used  to 
maintain  communication  between  machine  guns  in  rear  and  on  the 
flanks  and  the  troops  that  they  are  supporting. 

Telephones.— Connect  brigade,  battalion,  company  head- 
quarters, reserve  dugouts,  etc.,  with  the  guns,  normally.  The  guns 
are  also  connected  laterally. 

Orderlies. — Machine-gun  commanders  and  section  commanders 
also  have  a  sufficient  number  of  well-trained  orderlies  attached 
beforehand. 

Visual  signaling. — Ah  macnine  gunners  are  trained  in  sema- 
ohore  signaling. 


MACHINE  GUNS  IN  TRENCH  WARFARE.  85 

The  best  method  of  insuring  success  is: 

A  carefully  arranged  plan  of  action. 

To  have  plan  understood  by  all  concerned. 

Definite  orders  to  officers  and  machine-gun  commanders. 

Then  if  communication  breaks  down  the  individual  on  the  spot 
can  do  his  best  to  insure  the  success  of  the  general  plan. 

The  foregoing  will  guide  machine-gun  officers  in  choosing  their 
own  positions,  which  must  vary  according  to  the  ground  and  to  the 
tactical  requirements  of  the  situation. 

DEFENSE. 

For  the  defense  of  an  entrenched  line,  machine  guns  of  each 
section  must  be  arranged  by  one  officer. 

He  allots  areas  to  each  gun.    These  must  slightly  overlap. 

Whole  area  allotted  must  be  capable  of  being  seen  by  gunner — 
theoretical  marking  of  lines  of  fire  on  map  not  sufficient. 

Trench  map  prepared  showing  position  of  each  gun  and  area  swept 
by  it. 

Machine-gun  commanders  of  adjacent  brigades  must  confer  as  to 
their  flank  guns. 

Machine  guns  must  cover  areas  that  artillery  can  not  reach  or  can 
reach  with  difficulty. 

Aim  is  to  create  belts  of  machine-gun  fire  across  the  front. 

Machine  guns  are  so  placed  as  to  bring  oblique  or  enfilade  fire 
against: 

The  enemy  trenches. 

The  ground  over  which  he  must  pass  should  he  attack. 

Our  own  front  line  trenches  should  enemy  penetrate  into  them. 

To  achieve  these  objects,  machine  guns  may  be  placed: 

In  a  salient. 

In  a  reentrant. 

At  a  bend  in  the  trench. 

In  front  of  the  trench. 

In  or  near  support  or  communication  trenches. 

In  a  straight  portion  of  trench,  firing  through  oblique  loopholes. 

Emplacements  some  distance  in  front  of  the  trench,  concealed, 
and  approached  by  a  covered  sap  are  useful  both  for  attack  and 
defense. 

Machine  guns  are,  if  possible,  covered  from  fire  from  the  front 
while  being  able  to  sweep  the  front  of  the  entrenched  line  with 
cross-fire. 

While  firing  to  the  flank,  its  front  is  swept  by  the  fire  of  the  neigh- 
boring machine  gun. 


56  MACHINE   GUNS  IN  TRENCH  WARFARE. 

Arrangements  must  be  made  so  that  machine  guns  may  fire  to  the 
front  should  an  emergency  arise.  To  do  this: 

Arrange  so  that  some  sandbags  can  be  removed  thus  making  a 
loophole  to  the  front. 

Remember  that — 

If  sandbags  are  left  in  position  for  considerable  time  without  being 
moved,  they  may  become  embedded  and  be  found  immovable. 

Loopholes  filled  with  single  sacks  will  not  be  bullet  proof. 

Train  gunners  to  quickly  remove  the  maching  gun  from  the  tripod 
and  fire  over  the  parapet,  or  to  take  gun  and  tripod  and  fire  from  some 
previously  selected  spot.  These  methods  require  practice. 

Machine  guns  should  always  be  concealed  from  the  front. 

DISTRIBUTION. 

In  making  the  distribution  of  the  machine  guns,  the  following 
positions  should  be  considered: 

In  the  front  line  trenches. — In  a  stubborn  defense  they  may 
just  make  the  difference  between  success  and  failure. 

In  or  near  support  trenches. — To  prevent  further  advance  of 
the  enemy  should  they  capture  the  front  line,  to  enfilade  the  front 
line  should  it  be  captured,  and  to  sweep  communication  trenches. 

In  positions  in  rear. — Should  the  ground  be  favorable  they  can 
be  arranged  to: 

Fire  over  trenches  and  sweep  ground  in  front. 

Fire  through  gaps  in  the  line. 

Command  positions  where  the  enemy  can  concentrate  before 
attack. 

Command  covered  approaches  to  the  defensive  line. 

Command  likely  enemy  machine-gun  positions. 

Give  overhead  covering  fire  when  our  troops  attack. 

Use  indirect  fire  against  ground  in  rear  of  the  enemy's  lines. 

In  strong  places  just  in  rear. — These  positions  should  be  strong 
and  inconspicuous.  They  are  arranged  so  that  the  ground  in  front 
is  swept  by  cross-fire. 

Some  in  reserve. — These  are  used  for  instructional  purposes 
when  not  otherwise  required. 

The  number  of  guns  placed  in  each  of  these  divisions  will  depend 
upon  the  number  of  guns  available,  but  emplacements  should  be  pre- 
pared and  arrangements  made  to  place  machine  guns  in  any  of  these 
positions  if  they  should  be  required. 

ATTACK. 

The  Brigade  Machine-gun  Officer  must  be  fully  informed  of  the 
plan  of  operations  as  early  as  possible. 


MACHINE  GUNS  IN  TRENCH  WARFARE.  57 

He,  in  conjunction  with  the  officers  in  command  of  sections,  works 
out  the  detailed  plan  for  the  employment  of  the  machine  guns. 

The  brigade  machine-gun  officer  will — 

Make  a  study  of  the  enemy's  front  line  and  its  relation  to  his  own 
trenches. 

From  a  study  of  maps  make  himself  acquainted  with  the  ground 
in  rear  of  the  enemy  front  line,  and  also  with  his  trench  system. 
Aeroplane  maps  are  required  for  this. 

Issue  definite  orders  to  officers  commanding  the  different  sec- 
tions, as  to  the  employment  of  the  guns,  after  approval  of  the  higher 
commander. 

Make  certain  that  machine-gun  positions  which  he  will  require 
are  in  good  condition. 

In  this  manner,  each  machine  gun  or  group  of  guns  will  have  a 
specific  task.  Before  the  action  begins,  all  will  know  their  duties. 

All  machine  guns  must  be  in  their  allotted  places  before  the 
preliminary  bombardment  commences. 

Machine  guns  are  the  weapons  most  likely  to  hold  up  the  attack. 
Efforts  must  be  made  to  locate  enemy  machine  guns.  Certain  guns 
are  detailed  to  engage  these  guns  as  soon  as  the  bombardment  ceases. 

Machine  guns  have  definite  tasks  and  must  not  be  interfered  with 
by  other  officers. 

Machine  guns  will  be  allotted: 

Some  to  go  forward  with  the  attacking  infantry.— The 
number  will  depend  upon  the  front  to  be  attacked  and  the  nature 
of  enemy's  trenches. 

Their  role  will  be  to  make  good  the  ground  gained  by  the  infantry. 

They  go  forward  when  it  is  sure  that  the  infantry  is  established 
in  the  captured  trench. 

Teams  conceal  their  identity  as  machine-gun  teams,  by  mingling 
with  a  wave  of  the  infantry,  and  carrying  their  guns  inconspicuously. 

The  approximate  locality  where  each  machine  gun  will  be  mounted 
in  the  captured  line  should  be  settled  in  advance. 

Lewis  guns,  or  guns  with  light  mountings,  should  be  used  for 
this  work.  The  heavy  tripod  is  brought  forward  after  the  position 
is  consolidated. 

Some  to  cover  the  infantry  advance. — The  positions  of  these 
guns  will  depend  upon: 

The  lie  of  the  ground. 

The  nature  of  the  attack. 

The  position  of  our  own  and  the  enemy's  trenches. 


58  MACHINE  GUNS  IN  TRENCH  WARFARE. 

These  machine  guns  are  allotted  as  follows: 

Some  to  prevent  the  cross-fire  by  rifles  and  machine  guns  from 
the  enemy's  trenches  situated  on  the  flanks  of  the  attack. 

Some  to  bring  oblique  or  enfilade  fire  on  to  the  portion  of  the 
enemy  trenches  being  attacked. 

Some  to  sweep  the  ground  over  which  the  enemy's  reserves  may 
advance  to  the  counter  attack. 

Some  may  be  pushed  out  in  front  of  the  line,  to  keep  down  enemy 
fire  while  the  infantry  are  getting  out  of  the  trenches  and  through  the 
wire.  These  latter  may  be  in  saps,  crops,  or  folds  of  the  ground. 

When  the  attacking  infantry  masks  the  fire  of  the  machine  guns, 
they  should,  if  possible,  direct  their  fire  past  the  flanks  of  the  attack- 
ing troops,  so  as  to  keep  down  flanking  fire  and  prevent  flank  attacks. 

If  our  troops  are  required  to  lie  down  between  the  trenches,  the 
machine  guns  try  to  keep  down  the  fire  of  the  enemy's  rifles  and 
machine  guns. 

When  their  covering  role  is  completed,  the  machine  guns  auto- 
matically return  to  the  control  of  the  brigade  machine-gun  officer, 
who  will  give  further  orders. 

Some  in  reserve  under  the  brigade  commander. — These  are 
retained  as  a  real  reserve,  not  pushed  too  early  into  the  fight. 

From  positions  in  rear  they  may  be  used  to  sweep  ground  behind 
the  enemy's  front  line,  fire  against  counter  attacks,  etc. 

SEPARATE  PLANS. 

If  the  attack  is  to  consist  of  two  or  more  phases  (two  or  more  dis- 
tinct advances),  separate  plans  must  be  made  for  each. 

AMMUNITION  SUPPLY. 

Arrangements  for  ammunition  supply,  belt  or  strip  filling,  ammuni- 
tion depots,  etc.,  are  made  before  the  action  commences.  An  officer 
is  placed  in  charge  of  these  arrangements. 

POST  OF  BRIGADE  MACHINE-GUN  OFFICER. 

With  or  near  the  commander  of  the  troops.  He  provides  himself 
with  a  sufficient  number  of  trained  orderlies. 


MACHINE  GUNS  IN  TRENCH  WARFARE.  59 


auction  of  a  D«f ended  Area 


H«ad-| 
quarteri. 

Self-siutalnbg  strong  p^Cnt,   f«ln« 
tn  all  direct 

Vj- — i j^ 

\         /          te  »er»e  »s  rallying  yolat 


tion  trench. 
Latrine. 
Dre«sln(  station. 


Contain*  «uart*rs  aad  depot*  JO*  to 

40'  underground. 


Sniper*  *mplaceB«t. 
Bowling  arm. 


PLATE  1. 


60  MACHINE  GUNS  IN  TRENCH  WARFARE. 


PLATE  2. 


(.1 


62 


MACHINE   GUNS  IN  TRENCH  WARFARE. 


PLATE  4. 


TYPICAL 
SUPPORTING   POINT 


PRCPARLOAT  W»MT   AAJJ  C«.LE5t. FBCM  LATC3T  AVAJLAflLf  INTOfiMATi 


MACHINE  GUNS  IN  TKENCH  WARFARE.  63 


PLATE  5. 


64 


MACHINE   GUNS  IN  TRENCH  WARFARE. 


PeUili-  of_lrent_  1  int  trentli. 


Machine  fun  «r  «nij«r  e»plae»> 
•tntl  In   front   of  trnverte*. 


Barrow  pit   tt«k. 
and  (round  wir 


ThU    faco.lMld  up  Hill  bftlkct  work 
•r  with  burlap  and  chlektn-»lr« 


Tin  e«n  with  pebbles    imide  an    hung  on  tht  «ir*  to 
"regut»r"  thf  ippro«ch  of  boiib   thro»er«  at  night* 


£1  •  Machine  guit". 
T-  Traverse 

PLATE  6. 


MACHINE   GUNS  IN  TRENCH  WARFARE. 


65 


•—17 5 


66 


MACHINE  GUNS  IN  TRENCH  WARFARE. 


MACHINE  GUNS  IN  TRENCH  WARFARE. 


67 


BOMB  PROOF  M.C. 
-  EMPLACEMENT 

BIGHT  *  U«  FLAMK. 
OPCH  tMPtACIMINT 
reOHTAt  HM  AHO 

SMJNTU  p«oor 

WOK-OUT    POST. 


ftlCHT  M.C  EMV 
WITN  LOOK-OUT 
POST  «.  SAP 

COVtRIMC    REMOVE 


PLATE  9. 


68  MACHINE  GUNS  IN  TRENCH  WARFARE. 


-.,      ISilfi 

//      ggjsifc 

111  8^ 


MACHINE  GUNS  IN  TRENCH  WARFARE. 


69 


HIDDEN    M.G 
EMPLACEMENT 
.AT    CROSS  -ROADS 
IN  .A   VILLAGE 
PREPARED 
FOR    PEFE.NCE 


L 


^A!^ 


PLATE  11. 


70  MACHINE   GUNS  IN  TRENCH  WARFARE. 


RECTANGULAR     LOOP-HOLE 


INSIDE  DIMENSIONS 


THIS  IS  STRONGLY  MADE  OF  Z'  PLANKS  TO  SUPPORT  WtlGHT  OF  SANDBAGS  ON 
TOP.  SLIDING  STttL  PLATES  CAKK  ARRAN6ED  AS  IN  OTHER  LOOP-MOU.AM)  ALSO  A  LI6HT 
DINGED  DOOR  rORBLIISDING. 


LOOP-HOLE  BOX. 
A  A.  FIXEP  STEEL  PLATES  ON  END. . 


£>.  STEEL   SLJWTSC  DOOR,  ARRANGED  TO 
SLIDE  TO  RIGHT.  [THIS  M»YM  MAM  IN  TWO  MUTTS 

TO  SLIM    KICHT  AND    LtFT.^ 

C.C.  BATTENS  TO  MAKE  SLIDE  FOR  DOOR 


PLATE  12. 


MACHINE   GUNS  IN  TRENCH  WARFARE. 


71 


RANGE  CARDS. 


DEFENSE. 

(a)  Thick  line  first  to  reference  point  as  "orienting  line." 
(6)  Lines  correct  relative  length. 

(c)  Range  from  one  flank  to  the  other  in  order. 

(d)  Mark  lines  accurately. 

(e)  Describe  points  briefly  and  accurately. 
(/)  Describe  exact  point  from  whence  taken. 
(g)  All  names  in  block  letters. 


Emplacement  No.  6.    Midway  between  old  barn  on  right  and  small 

tree  on  left. 
72 


MACHINE  GUNS  IN  TRENCH  WARFARE.  73 

• 
ATTACK. 

(a)  First  take  range  to  objective,  then  halfway  point,  then  inter- 
mediate objects. 
(6)  Put  ranges  in  right-hand  column. 

(c)  Objects  must  be  in  line  of  advance  and  likely  to  be  easily 
recognized  when  reached. 

(d)  If  possible,  objective  should  be  visible  from  each  point  taken. 

(e)  Fill  in  left  column  with  range  from  objective  and  rule  through 
right  column. 


600 
1DOO 

1450 
2000 


1st  objective  Ridge 


of 


Gate 
Rendezvous. 


JOOO. 


551. 


PLATE  14. 


74 


MACHINE   GUNS  IN   TRENCH  WARFARE. 


The  graticule  card. 

[To  be  held  18"  from  eye.] 

FOR  MARK  VI  AMMUNITION. 


-200 


600 


-400 


-1000 


-800 

9 

-1200 


-1400 


-1600 


-1800 


300- — 


2000 


1500 


1900 


The  machine  gunner's  range  and  trajectory  card  with  angles  of  elevation 
etc.,  for  Mark  VI ammunition. 


Culmi- 

Range. 

Approxi- 
mate 
angles  of 

Rise  in 
minutes. 

nating 
point  of 
trajec- 

elevation. 

tory  in 

feet. 

Yards. 

0             , 

100 

10 

... 

200 

14 

~7 

300 

21 

6 

"i" 

400 

27 

8 

2 

500 

35 

9 

u 

600 

44 

13 

6 

700 

56 

13 

9 

800 

1     10 

12 

13 

900 

1    23 

15 

17* 

1,000 

1    38 

15 

23i 

1,100 

1    53 

16 

31J 

1,200 

2    11 

18 

41 

1,300 

2    28 

20 

52 

1,400 

2    49 

20 

66 

1,500 

3      9 

21 

82 

1,600 

3    30 

25 

100 

1,700 

3    55 

25 

122 

1,800 

4    22 

28 

146 

1,900 

4    50 

29 

174 

2,000 

5    20 

32 

206 

2,100 

5    53 

37 

241 

2,200 

6    29 

38 

282 

2,300 

7    11 

47 

325 

2,400 

7    57 

47 

374 

2,500 

8    46 

52 

429 

2,600 

9    39 

55 

489 

2,700 

10    37 

59 

558 

2,800 

11    37 

62 

637 

2,900 

12    41 

... 

MACHINE  GUNS  IN  TRENCH  WARFARE. 


75 


Trajectory  disks,  illustrating  the  cone  of  fire  as  it  will  appear  in  over- 
head fire,  etc., for  Mark  VI ammunition. 


Range. 

Diameter  of  disks. 

Height  of  center  of  disk  above 
ground,   muzzle  of  gun  is 
taken  as   being  20  inches 
above  ground. 

75  per 
cent 
cone. 

100  per 
cent 
cone. 

700  yards 
tra- 
jectory. 

800  yards 
tra- 
jectory. 

900  yards 
tra- 
jectory. 

Yards. 
100 
200 
300 
400 
500 
600 
700 
800 
1,000 
1,500 
2,000 

Ft.  ing. 
8J 
1    3J 
2    0 
2    SJ 
3    6 
4    0 
4    6 
5    6 
6    8 
10    0 
13    4 

Ft.  ins. 
2      0 
3      6 
5      0 
6      6 
8      0 
10      0 
12      0 
14      0 
16      0 
24      0 
32      0 

Ft.  ins. 
5      5 
8      6 
10      2 
10      7 
9      4 
5    11 

Ft.  ins. 
6      5 
10      6 
13      4 
14      8 
14      2 
12      1 
7      6 

Ft.  ins. 
8    Si 
12    10 
16    10 
19      6 
20      2 
19      0 
15      6 
9      1 

DEPTH  OF  ZONE  BEATEN  BY  75  PER  CENT  OF  SHOTS  FIKED  FROM  A 
MAXIM  GUN. 


Dispersion  of  cone. 

Depth. 

Width. 

Yards. 

Yards. 

Feet. 

500 

150 

4 

1,000 

70 

8 

1,500 

60 

13 

2,000 

50 

19 

PROBABLE   ERRORS  IN   RANGING   TO   BE   ALLOWED   FOR   WHEN 
DIRECTING  FIRE. 


Method  of  ranging. 

Per 
cent  of 
error. 

Extent  of  ground  to  be  searched 
to  overcome  probable  errors 
in  ranging. 

500 

yards. 

1,000 
yards. 

1,500 
yards. 

2,000 
yards. 

Judging  distance  
Judging  distance  com- 
bined  with   "key 
ranges"  

15 

10 
5 

Yards. 
150 

100 
50 

Yards. 
300 

200 
100 

Yards. 
450 

300 
150 

Yards. 
600 

400 
200 

Range-finding  instru- 
ments   

76 


MACHINE   GUNS  IN  TRENCH  WARFARE. 


The  graticule  card. 

[To  be  held  18"  from  eye.] 

FOR   MARK  VII  AMMUNITION. 


-1000 


1200 


-1400 


-1600 


-1800  _ 


2000 


1100 


1500 


1900 


Mark  VII  ammunition. 


Angles  of  elevation. 

Angle  of 
descent. 

Cul- 
mi- 

nat- 
ing 
point. 

Trajectory 
disk. 

Low- 
est 
shot 
100 
per 
cent 
cone 
below 
cen- 
ter of 
disk. 

Height  of  center  of 
disk  above 
ground. 

Verti- 
cal. 

Hori- 
zon- 
tal. 

700 
yards. 

800 

yards. 

900 
yards. 

100  yards.  .    .      12  5 
200  yards.   .     .      15 
300  yards.   .     .      18  5 
400  yards.   .     .      22  5 
500  yards.  .     .      27 
600  yards.   .     .      32  5 
700  yards.  .     .      38  5 
800  yards.   .     .      46 
900vards.   .     .      54 
1,000  yards.     .135 
1   1,100  yards.     .  1  14  5 
1,200  yards.     .  1  27 
1,300  yards.     .  1  41 
1,400  yards.     .  1  57 
1,500  yards.      .  2  15 
1,600  yards.     .  2  35 
1,700  yards.     .  2  58 
1,800  yards.     .  3  23  5 
1,900  yards.      .  3  52 
2,000  yards.     .  4  24 

.Feet. 

0  11 
1  10 
2    9 
3    8 
4    8 
5    7 
6    7 
7    6 

0    6 
1    0 
1    6 
2    0 
2    6 
3    0 
3    6 
4    0 

1    1 
2    2 
3    3 
4    4 
5    5 
6    6 
7    7 
8    8 

3    5 
5    8 
6    9 
6  11 
5  11 
3  10 

4    3 
7    2 
9    1 
9  10 
9    8 
8    2 
5    1 

5    0 
8  11 
11    4 
13    2 
13    9 
13    2 
10  10 
6    7 

0.6 
1.3 
2.3 
3.8 
6.1 
8.9 
12.8 
17.8 
24.1 
32.4 
42 
54 
69 
87 
108 
132 
161 
195 

lin  300 
1  in  180 
lin  120 
lin   90 
lin   67 
lin   50 
lin   40 
lin   30 
lin    24 
lin    20 
1  in    15 
lin    13 
lin    11 
lin     9 
lin     8 
lin     7 
lin     6 

Heights  ofti 

At  100  yar 
At  200  yar 
At  300  yar 
At  400  yar 
At  500  yar 
At  600  yar 
At  700  yar 

ajectories  above  line  ofsiglit 
at  800  yards. 

ds...                       ..29 

ds  .      57 

ds  7    6 

ds  .88 

ds  8    9 

ds  7    6 

ds  4    8 

75%  zones:  500  yards,  ?*  y,d! 

yards,  ii°yd?-;  1,500  yards, 
5 

:;  1,000 

10' 

MACHINE   GUNS  IN  TRENCH  WARFARE.  77 

Measurements  of  the  75  per  cent  cone,  Mark  VII  ammunition. 


Range. 

Vertical 
diameter. 

Hori- 
zontal 
diameter. 

Depth 
of  E.  B. 
zone. 

Feet. 

Feet. 

Yards. 

500 

5 

2* 

220 

800 

8 

4 

172 

1,000 

10 

5 

140 

1,200 

12 

7 

112 

1,500 

15 

10 

70 

OVERHEAD  FIRE. 
(a)  String  and  Card  Method  of  Overhead  Fire. 

— * 

"tvv.-" "iffETV  ANCLE  ., 


TRENCH 


SUPPORTED  TROOPS 

Safe  to  fire  overhead  until  troops  reach  "A.' 


(B)TMCEHT  SIGHT  METHOD 


ENEMY  800X 


AimnyM** 

focGunnm 

Sight  raised  400"  to  give  safety  angle  of  30  minutes  shown  by  dotted  line . 


o 


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